Question 1052537

Fiora starts riding her bike at 20 mph, then slows down to 12 mph. The whole trip of 70 miles takes her 4.5 hours. For what distance does she travel at 20 mph? 
<pre>With D as distance traveled at 20 mph, we get the following TIME equation: {{{D/20 + (70 - D)/12 = 4.5}}}
Solve for D.