Help I’m so confused

A

explanation:
liz and mike both started at 4:15 pm.

mike stopped 90 minutes later. if liz stopped half an hour less than mike, then that means she stopped 60 minutes later. this is because half an hour is 30 and 90-30= 60.

therefore, we would add 60 minutes (or 1 hour because 60 minutes= 1 hour) to when she started, which is 4:15 pm.

4:15 pm + 1 hour = 5:15 pm