Question

Bob is taking his son to look at colleges. The first college they plan to visit is 150 miles from their home. In the first hour they drive at a rate of 60 mph. If they want to reach their destination in 2 1/2 hours. what speed must they average for the remainder of their trip?

Answer 1

Let's find the remaining distance they must travel.

Total distance-distance covered
150-60=90 mi

Now, we need to find the average speed they need to travel per hour to reach the destination in 2.5 (2 1/2) hours.

90 mi/2.5 h=36 mi/h

They must travel at an average speed of 36mph to reach their destination in 2 1/2 hours.

Check:
60+36(2.5)
=120 mi

Answer 2

150 -60 = 90

2.5 hrs - 1 hr = 1.5

So 90÷1.5= 60mph

Explanation:

rate = (150-60*1)/(2.5-1) = 90/1.5 = 90/(3/2) = 60 mph