Welcome to Westonci.ca, where finding answers to your questions is made simple by our community of experts. Explore in-depth answers to your questions from a knowledgeable community of experts across different fields. Connect with a community of professionals ready to help you find accurate solutions to your questions quickly and efficiently.

Johnny was able to drive an average of 31 miles per hour faster in his car after the traffic cleared. He drove 16 miles in traffic before it cleared and then drove another 47 miles. If the total trip took 2 hours, then what was his average speed in traffic?

Sagot :

9514 1404 393

Answer:

  16 mi/h

Step-by-step explanation:

The time for a given leg of the trip is the distance divided by the speed. If t is the speed in traffic, the total trip time is ...

  16/t +47/(t+31) = 2

Multiplying by t(t+31), we get ...

  16(t +31) +47t = 2(t)(t+31)

  2t^2 -t -496 = 0 . . . . put in standard form

  (2t +31)(t -16) = 0 . . . . factor

The positive solution is t = 16.

Johhny's average speed in traffic was 16 mph.