Question

A contractor must hire 6 men and 8 boys for 6 days to do the same piece of work as 8 men and 15 boys could do in 4 days. Compare the efficiency ratio of the men and the boys.

1. 5 ∶ 1
2. 4 ∶ 1
3. 1 ∶ 2 
4. 3 ∶ 1 
5. None of these

Answer 1

Correct Answer - Option 4 : 3 ∶ 1 

Given:

6 men and 8 boys can do a work in 6 days.

8 men and 15 boys can do the same work in 4 days.

Formula:

Equate the work for 6 men and 8 boys and for 8 men and 15 boys and then compare.

Calculation:

6 men and 8 boys can do the work in 6 days.

So, 36 men and 48 boys can do that work in 1 day.

8 men and 15 boys can do the same work in 4 days.

So, 32 men and 60 boys can do that work in 1 day.

By equating,

36 men + 48 boys = 32 men + 60 boys

⇒ 4 men = 12 boys

⇒ 1 men = 3 boys

∴ The ratio of efficiency of men and boys is 3 ∶ 1.