Answer
15 mi/h and 30 mi/h
Work Step by Step
Sum of the distances they travel until they meet each other is 90mi
90 miles = distance traveled by the first one + distance traveled by the second one
distance=time$\times$speed
speed of the slower one : x
speed of the faster one: 2x
90miles=2hours$\times$(2x)+2hours$\times$(x)
90=2(2x)+2x
90=6x
x=15
2x=30
