Section – III

41. In Bilaspur village, 12 men and 18 boys completed construction of a primary health centre in 60 days, by working for 7.5 hours a day. Subsequently the residents of the neighbouring Harigarh village also decided to construct a primary health centre in their locality, which would be twice the size of the facility built in Bilaspur. If a man is able to perform the work equal to the same done by 2 boys, then how many boys will be required to help 21 men to complete the work in Harigarh in 50 days, working 9 hours a day?

A. 45 boys

B. 48 boys

C. 40 boys

D. 42 boys

Solution:

Twice the work done in Bilaspur = work done in Harigarh

\ 2 ´ (12 men + 18 boys) ´ 60 ´ 7.5 = M₂ ´ 50 ´ 9

(where M₂ is the work force in Harigarh)

2 ´ (24 boys + 18 boys) ´ 60 ´ 7.5 = M₂ ´ 450

Þ M₂ = 84 boys. (This includes the 21 men who are equivalent to 42 boys.)

= 21 men + 42 boys.

\ 42 boys will be required. Choice (D)