Question

A job can be completed by 12 men in 12 days. How many extra days will be needed to complete the job . if 6 men. leave after working for 6 days?

• A. 10 days
• B. 12 days
• C. 8 days
• D. 24 days

Answer 1

Answer: (B)

12 days

12 men can complete in 12 days 1 work 1 man can complete in 1 day $\frac{1}{12\times 12}$ part of the work
$\therefore$ men can complete in 6 days
$\frac{6\times 6}{12\times 12}$ part of the work = $\frac{1}{4}th$ of the work Number of remaining men = 6
Remaining work = $\frac{3}{4}$ $\because$ 12 men can complete 1 work in 12 days
6 men can complete $\frac{3}{4}$ work in $\frac{12\times 12\times 3}{6\times 4}=18$ days
$\therefore$ Number of extra days = 18 - 6 = 12 days