A certain number of men complete a piece of work in 60 days. If there were 8 men more, the work could be finished 10 days earlier. The number of men originally was ?

40

Let there were originally x number of carpenter .

Total work = efficiency × number of days

Total work  = 60 × x = 60x

8 men joined work . So work will completed  10 days earlier i.e. 50 days

total work by them = 50(x + 8)

As per questions,

60x = 50(x + 8)

60x = 50x + 400

10x = 400

 x = 40  is number of men