Category: ICSE

ML Aggarwal Class 7 Solutions Chapter 9 Linear Equations and Inequalities Ex 9.3 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 9 Linear Equations and Inequalities Ex 9.3

Question 1.
If the replacement set is (- 5, – 3, – 1, 0, 1, 3, 4), find the solution set of:
(i) x < -2
(ii) x > 1
(iii) x ≥ -1
(iv) -5 < x < 3
(v) -3 ≤ x < 4
(vi) 0 ≤ x < 7.
Solution:

Question 2.
Represent the following inequations graphically:
(i) x ≤ 3, x ∈ N
(ii) x < 4, x ∈ W
(iii) -2 ≤ x < 4, x ∈ I
(iv) -3 ≤ x ≤ 2, x ∈ I
Solution:

Question 3.
Solve the following inequations.
(i) 4 – x > -2, x ∈ N
(ii) 3x + 1 ≤ 8, x ∈ W
Also represent their solutions on the number line.
Solution:

Question 4.
Solve 3 – 4x < x – 12, x ∈ {-1, 0, 1, 2, 3, 4, 5, 6, 7}.
Solution:

Question 5.
Solve -7 < 4x + 1 ≤ 23, x ∈ I.
Solution:

ML Aggarwal Class 7 Solutions Chapter 9 Linear Equations and Inequalities Ex 9.1 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 9 Linear Equations and Inequalities Ex 9.1

Solve the following (1 to 9) equations:
Question 1.
(i) 2 (3 – 2x) = 13
(ii) \(\frac { 3 }{ 5 }\) y – 2 = \(\frac { 7 }{ 10 }\)
Solution:

Question 2.

Solution:

Question 3.
(i) 7(x – 2) = 2 (2x – 4)
(ii) 21 – 3(x – 7) = x + 20
Solution:

Question 4.

Solution:

Question 5.

Solution:

Question 6.

Solution:

Question 7.

Solution:

Question 8.
(i) y + 1.2y = 4.4
(ii) 15% of x = 21
Solution:

Question 9.
(i) 2p + 20% of (2p – 1) = 7
(ii) 3 (2x – 1) + 25% of x = 97
Solution:

Question 10.
Find the value of p if the value of x⁴ – 3x³ – px – 5 is equal to 23 when x = -2.
Solution:

ML Aggarwal Class 7 Solutions Chapter 6 Ratio and Proportion Ex 6.3 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 6 Ratio and Proportion Ex 6.3

Question 1.
6 bowls cost ₹ 90. What would be the cost of 10 such bowls?
Solution:

Question 2.
Ten pencils cost ₹ 15. How many pencils can be bought with ₹ 72?
Solution:

Question 3.
400 grams cake costs 80 rupees. How much would a 1.5 kg cake cost?
Solution:

Question 4.
A man earns ₹ 18000 in 3 months.
(i) How much time would he take to earn ₹ 30000?
(ii) How much money will he earn in 7 months?
Solution:

Question 5.
12 mangoes weigh 2.4 kg. What is the weight of 8 mangoes?
Solution:

Question 6.
If the weight of 12 sheets of thick paper is 40 grams, how many sheets of the same paper would weigh 2\(\frac { 1 }{ 2 }\) kilograms?
Solution:

Question 7.
A bus consumes 25 litres of diesel in covering a distance of 90 kilometres. How much diesel is needed to cover 288 kilometres?
Solution:

Question 8.
If \(\frac { 4 }{ 5 }\) metre cloth costs ₹ 36, find the cost of 2\(\frac { 1 }{ 5 }\) metres of cloth.
Solution:

Question 9.
If 15 men can pack 540 parcels per day, how many men are needed to pack 396 parcels per day?
Solution:

Question 10.
Which is a better buy 12 kg potatoes for ₹ 132 or 16 kg potatoes for ₹ 168?
Solution:

ML Aggarwal Class 7 Solutions Chapter 6 Ratio and Proportion Ex 6.2 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 6 Ratio and Proportion Ex 6.2

Question 1.
Which of the following statements are true?
(i) 2.5 : 1.5 :: 7.0 : 4.2
(ii) \(\frac { 1 }{ 2 } :\frac { 1 }{ 3 } =\frac { 1 }{ 3 } :\frac { 1 }{ 4 }\)
(iii) 24 men : 16 men = 33 horses : 22 horses.
Solution:

Question 2.
Check whether the following numbers are in proportion or not:
(i) 18, 10, 9, 5
(ii) 3, 3\(\frac { 1 }{ 2 }\), 4, 4\(\frac { 1 }{ 2 }\)
(iii) 0.1, 0.2, 0.3, 0.6
Solution:

Question 3.
Find x in the following proportions:
(i) x : 4 = 9 : 12
(ii) \(\frac { 1 }{ 13 }\) : x :: \(\frac { 1 }{ 2 }\) : \(\frac { 1 }{ 5 }\)
(iii) 3.6 : 0.4 = x : 0.5
Solution:

Question 4.
Find the fourth proportional to
(i) 42, 12, 7
(ii) \(\frac { 1 }{ 3 }\), \(\frac { 1 }{ 4 }\), \(\frac { 1 }{ 5 }\)
(iii) 3 kg, 12 kg, 15 kg
Solution:

Question 5.
Check whether 7, 49, 343 are in continued proportion or not.
Solution:

Question 6.
Find the third proportional to
(i) 36, 18
(ii) 5\(\frac { 1 }{ 4 }\), 7
(iii) 3.2, 0.8
Solution:

Question 7.
The ratio between the length and width of a rectangular sheet of paper is 7 : 5. If the width of the sheet is 20.5 cm, find its length.
Solution:

Question 8.
The ages of Amit and Archana are in the ratio 4 : 5. If Amit is 4 years 8 months old, find the age of Archana.
Solution:

ML Aggarwal Class 7 Solutions Chapter 6 Ratio and Proportion Ex 6.1 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 6 Ratio and Proportion Ex 6.1

Question 1.
Express the following ratios in simplest form:

Solution:

Question 2.
Find the ratio of each of the following in simplest form:
(i) ₹ 5 to 50 paise
(ii) 3 km to 300 m
(iii) 9 m to 27 cm
(iv) 15 kg to 210 g
(v) 25 minutes to 1.5 hours
(vi) 30 days to 36 hours
Solution:

Question 3.
If A : B = 3 : 4 and B : C = 8 : 9, then find A : C.
Solution:

Question 4.
If A : B = 5 : 8 and B : C = 18 : 25, then find A : B : C.
Solution:

Question 5.
If 3A = 2B = 5C, then find A : B : C.
Solution:

Question 6.
Out of daily income of ₹ 120, a labourer spends ₹ 90 on food and shelter and saves the rest. Find the ratio of his
(i) spending to income
(ii) saving to income
(iii) saving to spending.
Solution:

Question 7.
5 grams of an alloy contains 3\(\frac { 3 }{ 4 }\) grams copper and the rest is nickel. Find the ratio by weight of nickel to copper.
Solution:

Question 8.
A pole of height 3 meters is struck by a speeding car and breaks into two pieces such that the first piece is \(\frac { 1 }{ 2 }\) of the second. Find the length of both pieces.
Solution:

Question 9.
Heights of Anshul and Dhruv are 1.04 m and 78 cm respectively. Divide 35 sweets between them in the ratio of their heights.
Solution:

Question 10.
₹ 180 are to be divided among three children in the ratio \(\frac { 1 }{ 3 } :\frac { 1 }{ 4 } :\frac { 1 }{ 6 }\) Find the share of each child.
Solution:

Question 11.
A natural number has been divided into two parts in the ratio 7 : 11. If the difference between the two parts is 20, find the number and the two parts.
Solution:

Question 12.
A certain sum of money has been divided into two parts in the ratio 9 : 13. If the second part is ₹ 260, find the total amount.
Solution:

Question 13.
The ratio of the present ages of Anjali and Ashu is 2 : 3. Five years hence, the ratio of their ages will be 3 : 4. Find their present ages.
Solution:

Question 14.
The present ages of A and B are in the ratio 5 : 6. Three years ago, their ages were in the ratio 4 : 5. find their present ages.
Solution:

Question 15.
Two numbers are in the ratio 5 : 6. When 2 is added to first and 3 is added to second, they are in the ratio 4 : 5. Find the numbers.
Solution:

Question 16.
The ratio of number of boys to the number of girls in a school of 1430 students is 7 : 6. If 26 new girls are admitted in the school, find how many new boys may be admitted so that the ratio of number of boys to the number of girls may change to 8 : 7.
Solution:

Question 17.
Which ratio is greater?
(i) 5 : 6 or 6 : 7
(ii) 13 : 24 or 17 : 32
Solution:

ML Aggarwal Class 7 Solutions Chapter 5 Sets Check Your Progress for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 5 Sets Check Your Progress

Question 1.
Write the following sets in tabular form and also in set builder form:
(i) The set of even integers which lie between -6 and 10.
(ii) The set of two digit numbers which are perfect square.
(iii) {factors of 42}
Solution:

Question 2.
Write the following sets in roster form:
(i) {x : x = 5n, n ∈ I and -3 < n ≤ 13}
(ii) {x : x = n², n ∈ W and n < 5}
(iii) {x : x = n² – 2, n ∈ W and n < 4}
Solution:

Question 3.
Write the following sets in set builder form:
(i) {-14, -7, 0, 7, 14, 21, 28}
(ii) {1, 2, 3, 6, 9, 18}
Solution:

Question 4.
Classify the following sets into the finite set, infinite set the empty set. In the case of a (non-empty) finite set, mention the cardinal number.
(i) The set of even prime numbers.
(ii) {multiples of 9}
(iii) {x : x is a prime factor of 84}
(iv) {x : 2x + 5 = 1, x ∈ N}
(v) {x : x is a month of a year having less than 30 days}
(vi) {x | x is a month of a leap year having 28 days}
Solution:

Question 5.
In the following, determine whether A and B are equivalent sets and if so, whether A = B.
(i) A = {1, 3, 5}, B = {Red, Blue, Green}
(ii) A = {prime factors of 70}, B = {prime factors of 60}
(iii) A = {even natural numbers less than 10}, B = {odd natural numbers less than 10}
Solution:

Question 6.
Let P = {letters of SCHOOL} and Q = {letters of FALSE}, then State whether each of the following statement is true or false for the above sets:
(i) P ⊂ Q
(ii) Q ⊂ P
(iii) P ↔ Q
Solution:

Question 7.
State whether each of the following statement is true or false for the sets A, B and C where
A = {x | x ∈ N, x < 40 and x is a multiple of 6}
B = {x | x ∈ W, x ≤ 40 and x is a multiple of 8}
C = {x | x is a factor of 28}.
(i) A ↔ B
(ii) B ↔ C
(iii) A ↔ C
Solution:

ML Aggarwal Class 7 Solutions Chapter 7 Percentage and Its Applications Objective Type Questions for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 7 Percentage and Its Applications Objective Type Questions

Question 1.
Fill in the blanks:
(i) 6% of ₹ 50 = ……….
(ii) If 25% of a number is 12, then the number is ……….
(iii) The mixed fraction 1\(\frac { 3 }{ 4 }\) converted to percentage form is
(iv) If a number increases from 20 to 28, then the increasing percentage is ………
(v) If cost price is ₹ 400 and loss is 15%, then the selling price is ……..
(vi) The profit or loss percentage is always calculated on ……….
(vii) The simple interest on a sum of ₹ 5600 at 8% p.a. for one year is ……….
(viii) 135% converted to decimal is ………
(ix) ……… is 50% more than 60.
(x) 25 mL is ………… percent of 5 litres.
Solution:

Question 2.
State whether the following statements are true (T) or false (F):
(i) 20% more than 30 is 36.
(ii) The ratio 2 : 5 converted to percentage is 60%.
(iii) 6\(\frac { 1 }{ 4 }\) % expressed as a fraction is \(\frac { 1 }{ 16 }\).
(iv) 80% of 450 m is equal to 360 m.
(v) If a number decreases from 20 to 15, then the decrease is 25%.
(vi) If Feroz obtains 336 marks out of600 marks, then the percentage of marks obtained by him is 33.6.
(vii) 0.018 is equivalent to 8%.
(viii) 250 cm is 4% of 1 km.
(ix) If S.P. of an article is ₹ 540 and loss is ₹ 40, then its C.P. is ₹ 500.
(x) By selling a book for ₹ 50, a shopkeeper suffers a loss of 10%. The cost price of the books is ₹ 60.
Solution:

Multiple Choice Questions

Choose the correct answer from the given four options (3 to 16):
Question 3.
The ratio 2 : 3 expressed as percent is
(a) 40%
(b) 60%
(c) 66\(\frac { 2 }{ 3 }\) %
(d) 33\(\frac { 1 }{ 3 }\) %
Solution:

Question 4.
The ratio of Fatima’s income to her saving is 4 : 1. The percentage of money saved by her is
(a) 20%
(b) 25%
(c) 40%
(d) 80%
Solution:

Question 5.
225% is equal to
(a) 2 : 3
(b) 3 : 2
(c) 4 : 9
(d) 9 : 4
Solution:

Question 6.
If 30% of x is 72, then x is equal to
(a) 120
(b) 240
(c) 360
(d) 480
Solution:

Question 7.
If x% of 80 = 12, then x is equal to
(a) 15
(b) 20
(c) 25
(d) 30
Solution:

Question 8.
0.025 when expressed as a percent is
(a) 250%
(b) 25%
(c) 4%
(d) 2.5%
Solution:

Question 9.
In class, 45% of students are girls. If there are 22 boys in the class, then the total number of students in the class is
(a) 30
(b) 36
(c) 40
(d) 44
Solution:

Question 10.
What percent of \(\frac { 1 }{ 7 }\) is \(\frac { 2 }{ 35 }\) ?
(a) 20%
(b) 25%
(c) 30%
(d) 40%
Solution:

Question 11.
If a man buys an article for ₹ 80 and sells it for ₹ 100, then gain percentage is
(a) 20%
(b) 25%
(c) 40%
(d) 125%
Solution:

Question 12.
If a man buys an article for ₹ 120 and sells it for ₹ 100, then his loss percentage is
(a) 10%
(b) 20%
(c) 25%
(d) 16\(\frac { 2 }{ 3 }\)%
Solution:

Question 13.
The salary of a man is ₹ 24000 per month. If he gets an increase of 25% in the salary, then the new salary per month is
(a) ₹ 2500
(b) ₹ 28000
(c) ₹ 30000
(d) ₹ 36000
Solution:

Question 14.
On selling an article for ₹ 100, Renu gains ₹ 20. Her gain percentage is
(a) 25%
(b) 20%
(c) 15%
(d) 40%
Solution:

Question 15.
The simple interest on ₹ 6000 at 8% p.a. for one year is
(a) ₹ 600
(b) ₹ 480
(c) ₹ 400
(d) ₹ 240
Solution:

Question 16.
If Rohit borrows ₹ 4800 at 5% p.a. simple interest, then the amount he has to return at the end of 2 years is
(a) ₹ 480
(b) ₹ 5040
(c) ₹ 5280
(d) ₹ 5600
Solution:

Value Based Questions

Question 1.
One bad apple is accidentally mixed with some good apples in a basket. As a result of which 25% of the total apples go bad. Now the number of good apples in the basket is 30. Find the number of good apples kept in the basket previously. What will happen if one bad person is mixed with some good ones?
Solution:

Question 2.
There is a group of 50 people who are patriotic out of which 40% believe in non-violence. Find the number of persons who believe in non-violence. Explain the importance of non-violence in patriotism.
Solution:

Higher Order Thinking Skills (HOTS)

Question 1.
A person preparing medicine wants to convert 15% alcohol solution into 32% alcohol solution. Find how much pure alcohol should he mix with 400 mL of 15% alcohol solution to obtain it.
Solution:

Question 2.
A manufacturer sells an item to an agency at a profit of 25%. The agency sells the item to a shopkeeper at 10% profit and shopkeeper sells the item at a profit of 20%. If the selling price of the item is ₹ 594, find the manufacturing price.
Solution:

ML Aggarwal Class 7 Solutions Chapter 7 Percentage and Its Applications Ex 7.4 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 7 Percentage and Its applications Ex 7.4

Question 1.
Find the simple interest on:
(i) ₹ 350 for 2 years at 11% per annum
(ii) ₹ 20000 for 4\(\frac { 1 }{ 2 }\) years at 8\(\frac { 1 }{ 2 }\) % per annum
(iii) ₹ 648 for 8 months at 16\(\frac { 2 }{ 3 }\) % per annum. Also, find the amount in each case.
Solution:

Question 2.
Find the time when:
(i) simple interest on ₹ 2500 at 4% per annum is ₹ 200
(ii) simple interest on ₹ 12000 at 6\(\frac { 1 }{ 2 }\) % per annum is ₹ 2730
Solution:

Question 3.
Find the rate of interest when:
(i) simple interest on ₹ 1560 in 3 years is ₹ 585
(ii) simple interest on ₹ 1625 in 2\(\frac { 1 }{ 2 }\) years is ₹ 325.
Solution:

Question 4.
Find the principal when:
(i) simple interest at 16% per annum for 2\(\frac { 1 }{ 2 }\) years is ₹ 3840
(ii) simple interest at 7\(\frac { 1 }{ 2 }\) % per annum for 2 years 4 months is ₹ 2730.
Solution:

Question 5.
Find the rate of interest when:
(i) ₹ 1200 amounts to ₹ 1320 in 2 years
(ii) ₹ 300 amounts to ₹ 400 in 2 years.
Solution:

Question 6.
Find the time when:
(i) ₹ 1250 amounts to ₹ 1950 at 16% per annum
(ii) ₹ 6540 amounts to ₹ 8447.50 at 12\(\frac { 1 }{ 2 }\) per annum.
Solution:

Question 7.
₹ 14000 is invested at 4% per annum simple interest. How long will it take for the amount to reach ₹ 16240?
Solution:

Question 8.
An amount of money invested trebled in 6 years. Find the rate of interest earned.
Solution:

Question 9.
Find the principal when:
(i) final amount is ₹ 4500 at 20% per annum for 5 years
(ii) final amount is ₹ 2420 at 4% per annum for 2\(\frac { 1 }{ 2 }\) years.
Solution:

ML Aggarwal Class 7 Solutions Chapter 5 Sets Objective Type Questions for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 5 Sets Objective Type Questions

Mental Maths
Question 1.
Fill in the blanks:
(i) If x is not a member of the set A, then symbolically we write it as ……..
(ii) Each element of a set is listed once and only ……….. repetitions are removed.
(iii) A set that contains a limited number of different elements is called a ……… set.
(iv) Two finite sets are called equivalent if and only if they have ………. a number of elements.
Solution:

Question 2.
State whether the following statements are true (T) or false (F):
(i) A collection of books is a set.
(ii) If X = {letters of the word PRINCIPAL}, then the cardinal number of set X is 9.
(iii) If P = {letters of the word AHMEDABAD}, then n(P) = 6.
(iv) If A is any set, then A ⊂ A.
(v) An empty set is a subset of every set.
(vi) If set A = {0}, then n{A} = 0.
(vii) If A and B are two sets such that A ⇔ B, then A = B.
Solution:

Multiple Choice Questions

Choose the correct answer from the given four options (3 to 9):

Question 3.
Which of the following collection forms a set?
(a) Collection of 5 odd prime numbers
(b) Collection of 3 most intelligent students of your class
(c) Collection of 4 vowels of the English alphabet
(d) Collection of first 6 months of a year.
Solution:

Question 4.
The tabular form for the statement ‘Days of the week starting with the letter T’ will be
(a) {Days of week starting with letter T}
(b) {Tuesday, Thursday}
(c) {x | x is a day of the week starting with letter T}
(d) none of these
Solution:

Question 5.
A set with a limited number of distinct elements is called
(a) a finite set
(b) an infinite set
(c) both finite as well as an infinite set
(d) none of these
Solution:

Question 6.
The symbol ↔ stands for
(a) belongs to
(b) is a subset of
(c) is equivalent to
(d) none of these
Solution:

Question 7.
The empty set is denoted as
(a) {Φ}
(b) { }
(c) {0}
(d) 0
Solution:

Question 8.
The cardinal number n(A) = for A = {x : x is an odd prime number less than 20} is
(a) 8
(b) 7
(c) 9
(d) 10
Solution:

Question 9.
If A = {x | x is a positive mutliple of 3 less than 20} and B = {x | x is a prime number less than 20}, then n(A) + n(B) is
(a) 6
(b) 8
(c) 13
(d) 14
Solution:

ML Aggarwal Class 7 Solutions Chapter 7 Percentage and Its Applications Ex 7.3 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 7 Percentage and Its Applications Ex 7.3

Questions 1.
Rohan bought a calculator for ₹ 760 and sold it for ₹ 874. Find his profit and profit percentage.
Solution:

Question 2.
Kirti bought a saree for ₹ 2500 and sold it for ₹ 2300. Find her loss and loss percent.
Solution:

Question 3.
Tell what is profit or loss in the following transactions. Also find profit percent or loss percent in each case:
(i) Gardening shears bought for ₹ 250 and sold for ₹ 325.
(ii) A shirt bought for ₹ 250 and sold at ₹ 150.
Solution:

Question 4.
Rajinder bought one almirah for ₹ 4800 and the other for ₹ 3640. He sold the first almirah at a gain of 13\(\frac { 1 }{ 3 }\) % and the other at a loss of 15%. How much did he gain or lose in the whole deal?
Solution:

Question 5.
In a furniture shop, 24 tables were bought at the rate of ₹ 450 per table. The shopkeeper sold 16 of them at the rate of ₹ 600 per table and the remaining at the rate of ₹ 400 per table. Find his gain or loss percent.
Solution:

Question 6.
By selling a fan for ₹ 810, a dealer makes a profit of ₹ 60. What is the cost price of the fan? What is his profit percent?
Solution:

Question 7.
By selling a steel almirah for ₹ 3906, a manufacturer suffers a loss of ₹ 294. Find the cost price of the almirah and his loss percentage.
Solution:

Question 8.
The cost price of a flower vase is ₹ 120. If the shopkeeper sells it at a loss of 10%, find the price at which it was sold.
Solution:

Question 9.
I buy a T.V. for ₹ 10000 and sell it at a profit of 20%. How much money do I get for it?
Solution:

Question 10.
A shopkeeper sells an article at ₹ 300, thus earning a profit of 20%. Find the cost price of the article.
Solution:

Question 11.
A shopkeeper sells i n article at ₹ 320, thus suffering a loss of 20%. Find the cost price of the article.
Solution:

Question 12.
By selling a chair for ₹ 522, a shopkeeper makes a profit of 16%. What is its cost price?
Solution:

Question 13.
A trader sold some damaged garments for ₹ 7360 at a loss of 8%. Find the cost price of the garments.
Solution:

Question 14.
By selling a table for ₹ 3168, Rashid loses 12%. Find its cost price. What percent would he gain or lose by selling the table for ₹ 3870?
Solution:

Question 15.
By selling an article for ₹ 4550, Tony incurs a loss of 9%. What percent would he gain or lose by selling it for ₹ 4825?
Solution:

ML Aggarwal Class 7 Solutions Chapter 7 Percentage and Its Applications Ex 7.2 for ICSE Understanding Mathematics acts as the best resource during your learning and helps you score well in your exams.

ML Aggarwal Class 7 Solutions for ICSE Maths Chapter 7 Percentage and Its Applications Ex 7.2

Question 1.
Find:
(i) 15% of 250
(ii) 25% of 120 litres
(iii) 1% of 1 hour
(iv) 75% of 1 kg
(v) 120% of ₹ 250
(vi) 0.6% of 2 km
Solution:

Question 2.
8% of children of a class of 25 like getting wet in the rain. How many children like getting wet in the rain?
Solution:

Question 3.
Vasundhara ate 3 ice cream cups out of 20 kept in the fridge. What per cent did she eat?
Solution:

Question 4.
Express:
(i) 20 as a percentage of 50
(ii) 60 litres as a percentage of 40 litres
(iii) 90 cm as a percentage of 4.5 m
(iv) 350 g as a percentage of 5.6 kg
Solution:

Question 5.
What per cent is:
(i) 12 of 80
(ii) 25 paise of 4 rupees
(iii) 300 g of 2 kg
Solution:

Question 6.
A school team won 6 games this year against 4 games won last year. What is the per cent increase?
Solution:

Question 7.
The price of a shirt decreased from ₹ 80 to ₹ 60, find the percentage of decrease in the price of the shirt.
Solution:

Question 8.
My mother says, in her childhood petrol was ₹ 1 per litre. It is ₹ 65 per litre today. By what percentage has the prices of petrol gone up?
Solution:

Question 9.
Rate of basmati rice last year was ₹ 40 a kg. This year they are costly by 20%. What is the price this year?
Solution:

Question 10.
300 students took an exam. 28% failed. Calculate the number of students who passed the exam.
Solution:

Question 11.
Out of 15000 voters in a constituency, 60% voted. Find the number of voters who did not vote.
Solution:

Question 12.
20% of the length of a flagpole is painted green, 45% is painted yellow and the remaining red. If the length of the pole is 18 m, what length of it is painted red?
Solution:

Question 13.
Chalk contains 10% calcium, 3% carbon, 12% oxygen and the remaining sand. Find the amount of carbon and calcium (in grams) in 2\(\frac { 1 }{ 2 }\) kg of chalk. Also, find the amount of sand (in kg).
Solution:

Question 14.
Find the whole quantity if:
(i) 25% of it is 9
(ii) 75% of it is 15
(iii) 12% of it is ₹ 1080
(iv) 8% of it is 40 litres
Solution:

Question 15.
Mohini saves ₹ 400 from her salary. If this is 10% of her salary, then what is her salary?
Solution:

Question 16.
16% of the apples in a basket go bad. If there are 42 good apples in the basket, find the total number of apples in the basket.
Solution:

Question 17.
In an examination, a student has to secure 45% marks to pass the exam. If Varun got 251 marks and failed by 19 marks, what are the maximum marks?
Solution:

Question 18.
On a rainy day, 94% of the students were students absent on that day was 174, find the total strength of the school.
Solution:

Question 19.
40% of the population of a town are men and 39% are women. If the number of children is 12600, find the number of men.
Solutions:

Question 20.
If the price of a watch is increased by 15%, the increase in the price is ₹ 90. What was the price of watching earlier?
Solution:

Question 21.
(i) Find the number which when increased by 30% becomes 39.
(ii) Find the number which when decreased by 8% becomes 506.
Solution:

Question 22.
The price of a shirt is reduced by 7% to ₹ 465. What is its original price?
Solution: