Question

elena bikes 20 minutes each day. at a constant speed of 15 miles per hour for the first five minutes, then 12 miles per hour for the last 15 minutes

Answer 1

1. 15 miles per hour is 0.25 miles per minute (15/60=0.25)
5 x 0.25 = 1.25 minutes

2. 12 miles per hour is 0.2 miles per minute
15 x 0.2 = 3 minutes

Final ans= 4.25 minutes or 4 mins 15 sec