15 men were hired to plough a piece of land in 10 days. How many more men will be required to do the same job is 3 days?

A) 35

B) 40

C) 50

D) 30

15 men can pough  land =  10 days

1 man can plough land = 10 x 15=  150 days

To complete this job within 3 days men requried = 150/3

                                                                                         = 50 men