if jack walked 9 miles in 1 hour and 15 minutes , what was his rate of walking in miles per hour ?
"distance walked in 1 hour and 15 mins = 9 miles speed per hour = distance / time = 9 / ( 5 / 4 ) = 7.2 miles per hour answer e"
divide(multiply(9, const_60), add(15, const_60))