Question 1086475

Two planes make a 1680 mile flight, one flying 10 miles per hour faster than the other. The quicker plane makes the trip 4 hours faster. How long did it take the slower plane to complete the flight?
<pre>Let time slower plane takes be T
Then time faster plane takes = T – 4
We then get the following SPEED equation: {{{matrix(1,3, "1,680"/T, "=", "1,680"/(T - 4) - 10)}}}
Solve this to get a time of {{{highlight_green(matrix(1,2, 28, hours))}}} for the slower plane.