MATH SOLVE

4 months ago

Q:
# Kellen's boat travels 15 mph. find the rate of the river current if she can travel 2 mi upstream in the same amount of time she can go 4 mi downstream. (let xequalsthe rate of the current.)

Accepted Solution

A:

If the speed of the stream is x

Time is given by d/r , where r is the rate and d is the distance;

Rate for upstream = (15-x) mph and that of down stream is (15 +x) mph

The time taken will be the same;

Thus; 2/(15-x) = 4/(15+x)

cross multiplying;

30 +2x = 60 -4x

6x = 30

x =5

Therefore the rate of the river is 5 mph

Time is given by d/r , where r is the rate and d is the distance;

Rate for upstream = (15-x) mph and that of down stream is (15 +x) mph

The time taken will be the same;

Thus; 2/(15-x) = 4/(15+x)

cross multiplying;

30 +2x = 60 -4x

6x = 30

x =5

Therefore the rate of the river is 5 mph