30 men can complete a work in 10 days. They started working and after six days, 10 more men joined them. In how many days will the total work be completed?

Correct option is B

Given: 30 men can complete a work in 10 days. They started working and after six days, 10 more men joined them.

Formula Used: Work done = Number of men ×Number of days

Solution:

30 men can complete the work in 10 days.

Total work = 30 ×10 = 300 unit

Work done in 6 days by 30 men = 30 ×6 = 180 unit

Remaining work = 300 - 180 = 120 unit

After 6 days, 10 more men joined, making it 40 men.

Remaining work = 120 unit

Time to complete remaining work =$$\frac{120}{40}$$​ = 3 days

Total days = 6 + 3 = 9 days