Question

If 10 men dig a ditch in 12 days ,how long would 15 men take to dig it?

Answer 1

Let

x=amount of time it takes 15 men to dig the hole

10 men work at the rate of 1/12 hole per day

1 man works at the rate of 1/120 hole per day

15 men works at the rate of 15/120 hole per day

So, our equation to solve is:

(15/120)x=1 (1 hole, that is)

x=8 days

@skb