math
posted by nannypam on .
A long distance trucker traveled 240 miles in one direction during a snow storm. The return trip in rainy weather was accomplished at double the speed and took 5 hours less time. What is the speed going.

Time of first trip = 240/x
time of return trip = 240/(2x)
240/x  240/2x = 5
multiply each term by 2x
480  240 = 10x
10x = 240
x = 24
speed on first trip was 24 mph
speed on return trip was 48 mph
check:
time for 1st trip = 240/24 = 10 hrs
time for 2nd trip  240/48  5 hrs, which is 5 hrs less.