SOLUTION: Jane has swum 30 laps in the lagoon and is continuing to swim at a rate of 15 laps per hour. Tarzan has swum only 20 laps but is continuing to swim at a rate of 25 laps per hour. H

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Question 1089203: Jane has swum 30 laps in the lagoon and is continuing to swim at a rate of 15 laps per hour. Tarzan has swum only 20 laps but is continuing to swim at a rate of 25 laps per hour. How many hours will it be before the two have swum an equal number of laps?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
in 1 hour, they will both have swum 45 laps.

for jane:

y = 30 + 15x

for tarzan:

y = 20 + 25x

these 2 equations need to be solved simultaneously, meaning the same value of x solves both equations.

there are several ways to do this.

i'll use elimination this time around.

the 2 equations are:

y = 30 + 15x
y = 20 + 25x

the same value of y applies to both equations.
the same value of x applies to both equations.

this is because y represents the same number of laps that each will swim and x represents the same number of hours that each will swim.

subtract the second equation form the first to get:

0 = 10 - 10x

add 10x to both sides of the equation to get:

10x = 10

solve for x to get x = 10/10 = 1

jane has swum 30 laps and swims another 15 * 1 = 15 for a total of 45 laps.

tarzan has swum 20 laps and swims another 25 * 1 = 25 for a total of 45 laps.

solution looks good.

number of hours before the two have swum an equal number of laps is 1.