Question

39 men can build a bridge in 12 days, working 5 hours a day. In how many days will 30 men, working 6 hours a day, complete the work?

• A. 10
• B. 13
• C. 14
• D. 15

Answer 1

The correct option is B 13

$\frac{\text{Mandays}}{\text{Quantity of work}}=39\times 12\times \times 5=2340$
We know number of men is inversely proportinal to number of days, so
$=2340=30\times 6\times$ number of days
$=2340=180\times$ number of days
$=\frac{2340}{180}=$ number of days
$13=$ number of days