If 5 men take 3 hours to dig 3 holes how long will it take for two men to dig half a hole

This belongs in the mathmatics catagory, but:

5 men do 3 units of work in 3 hrs.

5 men do 1 unit of work in 1 hr.

1 man does 1/5 unit of work in 1 hr.

2 men do 2/5 units of work in 1 hr.

Therefore 2 men will take 5/2 hours to dig 1 hole and take 5/4 hrs to dig half a hole.

So the answer you're looking for is 1 hr 15 mins