SOLUTION: A consultant traveled 10 hours to attend a meeting. The return trip took only 9 hours because the speed was 7 moles per hour faster. What was the consultant's speed each way?

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Question 81850: A consultant traveled 10 hours to attend a meeting. The return trip took only 9 hours because the speed was 7 moles per hour faster. What was the consultant's speed each way?
Now, correct me if I am wrong, but wouldn't I also need a distance traveled in order to find the speed each way?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Knowing the distance is not necessary to solve this problem.
Use the distance formula d+=+rtfor each way.
d+=+r%5B1%5Dt%5B1%5D and
d+=+r%5B2%5Dt%5B2%5D Where r is the rate (speed) and t is the time of travel.
You know that the distance, d, is the same in both cases.
You also know that r%5B2%5D=r%5B1%5D%2B7
You know that t%5B1%5D+=+10 andt%5B2%5D+=+9
Making the appropriate substitutions, you'll get:
d+=+r%5B1%5D%2A10
d+=+%28r%5B1%5D%2B7%29%2A9
Set these two equations equal to each other and solve for r%5B1%5D
r%5B1%5D%2A10+=+%28r%5B1%5D%2B7%29%2A9 Simplify.
10r%5B1%5D+=+9r%5B1%5D%2B63 Subtract 9r%5B1%5D from both sides.
r%5B1%5D+=+63mph
r%5B2%5D+=+r%5B1%5D%2B7
r%5B2%5D+=+63%2B7
r%5B2%5D+=+70mph
Check:
63%2A10+=+630miles. This is the distance one-way.
70%2A9+=+630miles.