This solution starts by responding directly to what is ASKED FOR:
Development of the solution is easily done using the symbolic algebra available in
SureMath - the math software for 21st century problem solving.
Find the rate of the plane in miles per hour.
A simple concept is used: d=vt.
Everybody knows this relationship! The organized problem solution shows the student the reliable, common sense way to solve problems involving distance, time, and velocity.
The Answer Book solution provides no long-term guidance, being convenient only for the values given. The basic concept of d=vt is not mentioned.