Question 1025523
 David traveled 120 miles in one hour less than it took Emily to travel 360 miles.
 Emily could do this because she drove twice as fast as David.
 find the rates and Times of both 
:
Let s = D's speed
then
2s = E's speed
:
Write a time equation; time = dist/speed
E's time - D's time = 1 hr
{{{360/(2s)}}} - {{{120/s}}} = 1
reduce the 1st fraction
{{{180/s}}} - {{{120/s}}} = 1
{{{60/s}}} = 1
60 = s, D's speed
then
120 = E's speed
:
Find the their times
{{{360/120}}} = 3 hrs
{{{120/60}}} = 2 hrs