Question

5 men and 12 boys finish a piece of work in 4 days, 7 men and 6 boys do it in 5 days. The ratio between the efficiencies of a man and boy is?
A. 1:2 B. 2:1 C. 2:3 D. 6:5 ​

Answer 1

$men \: 5 + 7 \\ = 12 \\ boys \: 12 + 6 \\ = 18$

:

12:18

2:3