Ram employs some men to do a piece of work in 100 days working 6 hours a day. But after working for 60 days they went on strike due to which the work was disrupted for 10 days and there was no work during strike. After that Ram employed 3 additional men to finish the work in time and he also increased the working hours by 1 hour. Find the initial number of men Ram employed?
Let, Initial number of men employed = y
Working hours needed by y men to complete the work = 100 × 6 = 600
[? They can complete the work in 100 days working 6 hours a day]
Before strike they worked for = 60 × 6 =360 working hours
According to the question,
No. of men employed after strike = y + 3
No. of days worked after strike=100 - (10 + 60) = 30
[? 60 days worked before the strike and 10 days strike]
No. of hours worked per day after strike = 6 + 1 = 7
⇒ y × (600 - 360) = (y + 3) × 30 × 7
⇒ 240y = 210y + 630
⇒ 30y = 630
⇒ y = 21
∴ The initial number of men Ram employed = 21