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24 votes
24 votes
PLS HELP

Jen traveled from Boston to Cape Cod at 60 mph. On her way back, the

traffic was bad and her return trip took 3 times as long. What was Jen's

average speed on the round trip?

User Deneene
by
2.9k points

1 Answer

20 votes
20 votes

Answer: 30 mph

Explanation: As we know: the formula for Average Speed (AS) is Average Speed = Total Distance ÷ Total Time.

Since we don't know exactly how far Jen needed to drive, our distance there will be 1, and since we don't know how long it took to get there, we will put 1 as well.

Now we have to state the distance and time to get back. The distance will stay the same so we keep it 1. Now it is stated that when returning, it took Jen 3 times slower to get back, so we do 1 × 3 (because it took her longer) and get 3.

Next, we substitute: AS=TD÷TT ⇒ AS= (1+1) ÷ (1+3) = 2 ÷ 4= 1/2 or 1.4

Since our given beginning speed was 60mph, we need to multiply by 1/2 to get the final answer:

1/2 x 60 = 30

So ya, this is the answer *100% correct, checked on another website*

User Paulo Buchsbaum
by
3.2k points