What are 3 twelfths of 4 hours?

There are 60 minutes in an hour

A twelfth of an hour is 5 minutes,

Three-twelfths of one hour is (3 x 5) = 15 minutes.

Three-twelfths of four hours is (4 x 15) = 60 minutes.

So, three-twelfths of 4 hours is 1 hour.