Algebra problem, PLEASE HELP ME?
It took John 12 hours riding his bike to make the round trip to his uncle's. if he averaged 20 mph out and 30 mph back, how long did he travel each way? (Round to the nearest tenth).
What is the out hours, and the back in hours??
Comments
Let d = dist traveled one way
Write a time equation;
time = dist/speed
d/20+d/30 = 12
answer:
http://www.algebra.com/algebra/homework/word/trave...
Let the distance to his uncle's house be X miles
X / 20 + X /30 = 12
MULTIPLY BY 60
3X + 2X = 720
5X = 720
X = 144 miles
GOING = 144/20 = 7.2 hours ANSWER
RETURNING = 144/30 = 4.8 hours ANSWER