Write a real problem you could answer by solving the equation - 8x+60=28

Bob found out that he can dig 8 inches down every minute. If he wants to put a 5 foot stick in the hole with 28 inches showing, how long does he have to dig?

(so to solve you convert 5 feet to 60 inches then do the equation - 8x+60=28 then you add 8x to both sides, subtract 28 then divide by 8 leaving you with 4 minutes)