Answers

2016-04-04T19:03:58+05:30
15 men can complete 1/3 of the job in 7 days
15 men can complete the job in 21 days
x men can complete the job in 5 days
x = 
 \frac{15*21}{5}
x = 63 men is needed to complete the job in 5 days.

0
options are 20, 21, 45, 63
sorry i made a mistake
its 5 not 3
now i corrected