60 men could complete a piece of work in 250 days. They worked together for 200 days. After that work had to be stopped for 10 days due to bad weather. How many more men should be engaged to complete the work in time ?

60 men work for 200 days.
They stops for 10 day due to bad weather.
So, the work is to complete in
= (50 - 10)
= 40 days
In order to complete in scheduled time i.e., 250 days.
Let 'n' number of more men is required
(60_men × 200_days) +{(60 + n)_men × 40_days} = 60_men × 250_days
⇒ 12000 + {(60 + n)_men × 40_days} = 15000
⇒ (60 + n)40_days = 3000
⇒ 60 + n = 75
⇒ n = 15

Alternate :
60 men can complete a work in 250 days.
But they work for 200 days.
Then remaining days = 50 days
So,
60 × 50 = 60 + x × 40
⇔ x = 15