We already know that 1 mile = 5280 foot
Also we know that 1 hour = (60 * 60) seconds
= 3600 seconds
Then
24 miles per hour = (24 * 5280)/3600
= 126720/3600
= 35.2 feet/sec
So 24 miles/hour is equal to 35.2 feet per second. The only important thing is to know the conversions correctly. Then the problem becomes easy to solve. I hope the conversions and the procedure for solving the question is clear to you and in future you will be able to do such problems on your own without requiring any help.
