A certain number of men can do a work in 60 days. If there were 8 men more it could have finished in 10 days less. How many men were there?

Correct option is B

Given
Time 1 = 60 days, Extra men = 8, Time 2 = 50 days (10 days less)

Formula Used
​$$M_1 D_1 = M_2 D_2$$​​

Solution
​$$x \times 60 = (x + 8) \times 50 \\60x = 50x + 400\\10x = 400 \Rightarrow x = 40 men$$​​
Final Answer
So the correct answer is (b)