Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

It takes Ginny's motor boat?

It takes Ginny's motor boat 4 hours to travel downstream 20 miles and 2 hours to travel 2 miles upstream from her camp. What is the average speed of the current?

1 Answer

Relevance
  • 7 years ago
    Favorite Answer

    4(s + c) = 20 or 4s + 4c = 20

    2(s - c) = 2 or 2s - 2c = 2 or s = 2 + c

    substitute second equation into first equation:

    4(2 + c) + 4c = 20

    8 + 4c + 4c = 20

    8c = 12

    c = 12/8 = 1.5 mi/hr

    The current speed is 1.5 miles per hour.

    - .--

Still have questions? Get your answers by asking now.