## RS Aggarwal Class 7 Solutions Chapter 9 Unitary Method Ex 9C

These Solutions are part of RS Aggarwal Solutions Class 7. Here we have given RS Aggarwal Solutions Class 7 Chapter 9 Unitary Method Ex 9C.

**Other Exercises**

- RS Aggarwal Solutions Class 7 Chapter 9 Unitary Method Ex 9A
- RS Aggarwal Solutions Class 7 Chapter 9 Unitary Method Ex 9B
- RS Aggarwal Solutions Class 7 Chapter 9 Unitary Method Ex 9C
- RS Aggarwal Solutions Class 7 Chapter 9 Unitary Method CCE Test Paper

**Objective Questions.**

**Marks (✓) against the correct answer in each of the following :**

**Question 1.**

**Solution:**

(c)

Weight of 4.5 m rod = 17.1 kg

**Question 2.**

**Solution:**

(d) None of these 0.8 cm represent the map = 8.8 km

**Question 3.**

**Solution:**

(c) In 20 minutes, Raghu covers = 5 km

in 1 minutes, he will cover = \(\frac { 5 }{ 20 }\) km

and in 50 minutes, he will cover

**Question 4.**

**Solution:**

(d)

No. of men in the beginning = 500

More men arrived = 300

No. of total men = 500 + 300 = 800

For 500 men, provision are for = 24 days

For 1 man, provision will be = 24 x 500 days (less men, more days)

and for 800 men, provision will be = \(\frac { 24 }{ 800 }\) x 500 days

(more men less days)

= 15 days

**Question 5.**

**Solution:**

(b) Total cistern = 1

Filled in 1 minute = \(\frac { 4 }{ 5 }\)

Unfilled = 1 – \(\frac { 4 }{ 5 }\) = \(\frac { 1 }{ 5 }\)

\(\frac { 4 }{ 5 }\) of cistern is filled in = 1 minutes = 60 seconds

1 full cistern can be filled in = \(\frac { 60 x 5 }{ 4 }\) = 75 seconds

More time = 75 – 60 = 15 seconds

**Question 6.**

**Solution:**

(a)

15 buffaloes can eat as much as = 21 cows

1 buffalo will eat as much as = \(\frac { 21 }{ 15 }\) cows

35 buffaloes will eat as much as

= \(\frac { 21 x 35 }{ 15 }\) cm = 49 cows

**Question 7.**

**Solution:**

(b) 4 m long shadow is of a tree of height = 6 m

1 m long shadow of flagpole will of height = \(\frac { 6 }{ 4 }\) m

50 m long shadow, the height of pole 6 will be = \(\frac { 6 }{ 4 }\) x 50 = 75 m

**Question 8.**

**Solution:**

(b) 8 men can finish the work in = 40 days

1 man will finish it in=40 x 8 days (less men, more days)

8 + 2 = 10 men will finish it in = \(\frac { 40 x 8 }{ 10 }\) days

(more men, less days)

= 32 days

**Question 9.**

**Solution:**

(b)

16 men can reap a field in = 30 days

1 man will reap the field in = 30 x 16 days

and 20 men will reap the field in = \(\frac { 30 x 16 }{ 20 }\) = 24 days

**Question 10.**

**Solution:**

(c) 10 pipe can fill tank in = 24 minutes

1 pipe will fill it in = 24 x 10 minutes (less pipe, more time)

and 10 – 2 = 8 pipes will fill the tank in

= \(\frac { 24 x 10 }{ 8 }\) = 30 minutes

**Question 11.**

**Solution:**

(d) 6 dozen or 6 x 12 = 72 eggs

Cost of 72 eggs is = Rs. 108

Cost of 1 egg will be = Rs. \(\frac { 108 }{ 72 }\)

and cost of 132 eggs will be 108

= Rs. \(\frac { 108 }{ 72 }\) x 132 = Rs. 198

**Question 12.**

**Solution:**

(b) 12 workers take to complete the work = 4 hrs.

1 worker will take = 4 x 12 hrs. (less worker, more time)

15 workers will take = \(\frac { 4 x 12 }{ 15 }\) hrs. (more workers, less time)

= \(\frac { 16 }{ 5 }\) hr. = 3 hrs. 12 min

**Question 13.**

**Solution:**

(a) 27 days – 3 days = 24 days

Men = 500 + 300 = 800

For 500 men, provision is sufficient = 24 days

For 1 man, provision will be = 24 x 500 (less man, more days)

and for 500 + 300 = 800 men provision

will be sufficient = \(\frac { 24 x 500 }{ 800 }\) = 15 days

(more men, less days)

**Question 14.**

**Solution:**

(c) No. of rounds of rope = 140

Radius of base of cylinder = 14 cm

Radius of second cylinder of cylinder = 20 cm

If radius is 14 cm, then rounds of rope are = 140

If radius is 1 cm, then round = 140 x 14 (less radius more rounds)

and if radius is 20 cm, then rounds will

be = \(\frac { 140 x 14 }{ 20 }\) = 98 (more radius less rounds)

**Question 15.**

**Solution:**

(d) A worker makes toy in \(\frac { 2 }{ 3 }\) hr= 1

He will make toys in 1 hr = 1 x \(\frac { 3 }{ 2 }\)

and will make toys in \(\frac { 22 }{ 3 }\) hrs. = 1 x \(\frac { 3 }{ 2 }\) x \(\frac { 22 }{ 3 }\)

= 11 (more time more toys)

**Question 16.**

**Solution:**

(d) A wall is constructed in 8 days by = 10 men

It will be constructed in 1 day by = 10 x 8 men (less time, more men)

10 x 8

More men required = 160 – 10 = 150

Hope given RS Aggarwal Solutions Class 7 Chapter 9 Unitary Method Ex 9C are helpful to complete your math homework.

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