1.  3 men can do a piece of work in 18 days. 6 children can also do that work in 18 days. 4 men and 4 children together will finish the work in how many days ?
A. 10
B. 6
C. 12
D. 19
E. None of the above

Answer: Option D

Explanation:

3 men = 6 children

⇒ 1 man = 2 children

∴ 4 men + 4 children = 4 men + (4/2) men = 6 men

Given, M1 = 3, M2 = 6, D1 = 18, W1 = W2 = 1 and D2= ?


According to the formula,

M1D1W2 = M2D2W1

⇒ 3 x 18 x 1 = 6 x D2 x 1

∴ D2 = 3 x 18/6 = 9 days