SOLUTION: Ricky drove from Town A to Town B in 3 hours. His return trip from Town B to Town A took 5 hours because he drove 15 miles per hour slower on the return trip. How fast did Ricky d

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Question 107682: Ricky drove from Town A to Town B in 3 hours. His return trip from Town B to Town A took 5 hours because he drove 15 miles per hour slower on the return trip.
How fast did Ricky drive on the trip from Town A to Town B?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
You must begin with the firmly held conviction that nobody picked up Town A and moved it during the 8+ hours that Ricky was gone.
We know that d=rt

For the initial trip, we only know that t = 3, so:

d=3r

For the return trip, we know that t = 5 and r is 15 mph slower, so:

d=5%28r-15%29

Since the distance going is the same as the distance returning, we can say:

3r=5%28r-15%29

Simplify and solve:

3r=5r-75
-2r=-75
r=37.5 mph

Check:
Does 3%2A37.5=5%2837.5-15%29? I'll leave the arithmetic for you.