MHB Bob & Son: Need Help Figuring Out College Trip Speed!

[lpollard8985]

I am a parent trying to help my son figure out this problem... Please HELP!

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 60mph. If they want to reach their destination in 2.5 hours, what speed must they average for the remainder of their trip?

 

[soroban]

Hello, lpollard8985!

Both of you are stumped by this problem?

Bob is taking his son to look at college.
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 2.5 hours,
what speed must they average for the remainder of their trip?

In the first hour, they drove 60 miles.

They must drive the remaining 90 miles in 1.5 hours.

What speed is necessary?