MathDB
Average Rate

Source:

March 3, 2010
rate problems

Problem Statement

A man drives 150 150 miles to the seashore in 3 3 hours and 20 20 minutes. He returns from the shore to the starting point in 4 4 hours and 10 10 minutes. Let r r be the average rate for the entire trip. Then the average rate for the trip going exceeds r r in miles per hour, by: <spanclass=latexbold>(A)</span> 5<spanclass=latexbold>(B)</span> 412<spanclass=latexbold>(C)</span> 4<spanclass=latexbold>(D)</span> 2<spanclass=latexbold>(E)</span> 1 <span class='latex-bold'>(A)</span>\ 5 \qquad <span class='latex-bold'>(B)</span>\ 4 \frac{1}{2} \qquad <span class='latex-bold'>(C)</span>\ 4 \qquad <span class='latex-bold'>(D)</span>\ 2 \qquad <span class='latex-bold'>(E)</span>\ 1