math

posted by .

A river has a current of 4 mph. Find the speed of Simon’s boat in still water if it goes 40 miles downstream in the same time as 24 miles upstream.

  • math -

    speed of boat ---- x mph
    speed downstream = x+4
    speed upstream = x-4

    time upstream = 24/(x-4)
    time downstream = 40/(x+4)

    40/(x+4)= 24/(x-4)
    cross-multiply
    40x - 160 = 24x + 96
    16x = 256
    x = 16

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. algebra

    Show a complete solution. Upstream, downstream. Junior’s boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the …
  2. algebra

    36 Upstream, downstream. Junior’s boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the current?
  3. Math

    A boat, which moves at 18 mph in still water, travels 14 miles downstream in the same amount of time it takes to travel 10 miles upstream. Find the speed of the current.
  4. math

    River Current A boat can travel 36 miles upstream in the same time that it can travel 54 miles downstream. If the speed of the current is 3 miles per hour, find the speed of the boat without a current.
  5. math

    The speed of a stream is 6 mph. If a boat travels 52 miles downstream in the same time that it takes to travel 26 miles upstream, what is the speed of the boat in still water?
  6. Math

    Brian's boat has a top speed of 9 miles per hour in still water. While traveling on a river at top speed, he went 10 miles upstream in the same amount of time he went 20 miles downstream. Find the rate of the river current.
  7. algebra

    Rita’s boat has a top speed of 12 miles per hour in still water. While traveling on a river at top speed, she went 20 miles upstream in the same amount of time she went 40 miles downstream. Find the rate of the river current.
  8. MAth

    John can travel 8 miles upstream in the same time it takes him to go 12 miles downstream. His boat goes 15 mph in still water. What is the rate of the current/
  9. Algebra

    A boat has a speed of 20 mph in still water. While traveling on a river at top speed, it went 40 miles upstream in the same amount of time it went 60 miles downstream. Find the rate of the river current.
  10. math

    The speed of a river current is 4 mph. IF a boat travels 20 miles downstream in the same time that it takes to travel 10 miles upstream, find the speed of the boat in still water.

More Similar Questions