A contractor was given work to be finished in 200 days. He hired 40 workers to finish the work in the given time. However, after 50 days he found that only 20% of the work has been completed. What is the minimum number of workers should he be hiring more to ensure that the project is completed on time. Assume all workers are equally efficient

14 , But CAT usually prefers asking questions with exact answers wrt Time & Work.

Hi
MDH/W is constant for work problems
so MDH/W for 50 days will be equal to MDH/W for remaining 150 days
So we get 40*50/0.2W = M*150/0.8W
solving we get M=160/3
So more men required will be 160/3 -40 = 40/3
Now as men has to be integers so it will be just greater than 40/3 so we get 14 (Note with 13 work will not be completed )
so 14 more men are required.

14