Question 921605

A small airplane flies 1120  miles with an average speed of 280  miles per hour. 2  hours after the plane leaves, a Boeing 747  leaves from the same point. Both planes arrive at the same time; what was the average speed of the 747 ?
<pre>
Time small airplane traveled for: {{{1120/280}}}, or 4 hours
Boeing 747 takes 2 hours less, or 4 – 2, or 2 hours 
Speed of 747: {{{1120/2}}}, or {{{highlight_green(highlight_green(560))}}} mph