## RS Aggarwal Class 8 Solutions Chapter 12 Direct and Inverse Proportions Ex 12C

These Solutions are part of RS Aggarwal Solutions Class 8. Here we have given RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12C.

Other Exercises

OBJECTIVE QUESTIONS :
Tick the correct answer in each of the following :

Question 1.
Solution:
Cost of 14 kg of pulses = Rs 882
Cost of 1 kg of pulses Rs $$\\ \frac { 882 }{ 14 }$$
Cost of 22 kg of pulses = Rs $$\frac { 882\times 22 }{ 14 }$$
= 63 x 22
= Rs 1386

Question 2.
Solution:
Let x be oranges which can be bought for Rs. 33.80
8 : x : : 10.40 : 33.80
=> x × 10.40 = 8 x 33.80
=> $$\frac { 8\times 33.80 }{ 10.40 }$$
=> $$\frac { 8\times 3380 }{ 1040 }$$
= 26
∴ No. of oranges = 26 Ans. (c)

Question 3.
Solution:
No. of bottles 420 x
Time 3 5
More time, more bottles
By direct proportion
420 : x :: 3 : 5
x = $$\frac { 420\times 5 }{ 3 }$$
= 700
∴ No. of bottle will be 700 (b)

Question 4.
Solution:
Distance covered 75 km x
Time taken 60 min. 20 min.
Less time, less distance By direct proportion,
75 : x :: 60 : 20
x = $$\frac { 75\times 20 }{ 60 }$$
= 25
∴ Distance covered = 25 km (a)

Question 5.
Solution:
No. of sheets 12 : x
Weight 40 g : 1000 g
More weight, more sheets
By direct proportion 12 : x :: 40 : 1000
x = $$\frac { 12\times 1000 }{ 40 }$$
= 300
∴ No. of sheets = 300 (c)

Question 6.
Solution:
Let x be the height of tree
Height of pole 14 m : x m
Length of shadow 10 m : 7 m
By direct proportion 14 : x :: 10 : 7
x = $$\frac { 14\times 7 }{ 10 }$$
= $$\\ \frac { 98 }{ 10 }$$
= 9.8 m
∴ Height of the = 9.8 m (b)

Question 7.
Solution:
Let actual length of bacteria = x cm
Enlarged (times) 50000
Length 5 cm
Then actual length (x)
Then $$\frac { x\times 50000 }{ -4 }$$
= 5
=> x = $$\\ \frac { 5 }{ 50000 }$$
= $$\\ \frac { 1 }{ 10000 }$$
= 10 cm (c)

Question 8.
Solution:
No. of pipes 6 : 5
Time taken to 120 min : x min
fill the tank
Less pipes, more time
By inverse proportion 6 : 5 :: x : 120
x = $$\frac { 6\times 120 }{ 5 }$$
= 144 (b)
∴ Time taken = 144 minutes

Question 9.
Solution:
Let number of days = x, then
Persons 3 : 4
(Time taken to build a wall) 4 : x
More person, less time take
By inverse proportion,
3 : 4 :: x : 4
x = $$\frac { 4\times 3 }{ 4 }$$
= 3 (b)
∴ Time taken to build the wall = 3 days

Question 10.
Solution:
Let time taken will be x hrs
Speed 60 km/h : 80 km/h
Time taken to 2hr : x
reach
(More speed, less time)
By inverse proportion 60 : 80 :: x : 2
x = $$\frac { 60\times 2 }{ 80 }$$
= $$\\ \frac { 3 }{ 2 }$$
∴ Time take $$\\ \frac { 3 }{ 2 }$$ hours or 1 hr. 30 m in. (a)

Hope given RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12C are helpful to complete your math homework.

If you have any doubts, please comment below. Learn Insta try to provide online math tutoring for you.