Question

Tyrone almost forgot that he promised to pick up a prescription for his mother at the drug store across town. His mother is due home in 45 minutes. If Tyrone is able to make the 12.5 mile trip to the store and back again before his mother gets home, can he obey the posted speed limit of 35 mph?

Answer 1

The round trip is 12.5 miles * 2 way = 25 miles. In order to accomplish this in 45 minutes, or 45/60 = 0.75 hours, Tyrone would have to drive at a speed of 25 miles / 0.75 hours = 33.3 miles per hour. If he were to actually be able to drive continuously at this speed without stopping and the prescription pickup were instantaneous, then he would be able to make the round trip in time. However, in the real world this is unlikely to be the case.