Question 292597
Using the butterfly stroke to swim the length of the pool, Mark averaged 1.5 meters per second.
Swimming back, he used the breast stroke and averaged 1.2 meters per second.
 the entire swim took 1 minute and 15 seconds. how long is the pool?
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Let d = the length of the pool (in meters)
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Change 1 min 15 sec to 75 seconds
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Write a time equation; Time = dist/speed
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Butterfly time + Breaststroke time = 75 sec
{{{d/1.5}}} + {{{d/1.2}}} = 75
multiply equation by 6, results
4d + 5d = 6(75)
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9d = 450
d = {{{450/9}}}
d = 50 meters is the length of the pool
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Check solution by finding the time
{{{50/1.5}}} + {{{50/1.2}}} =
33.33 + 41.67 = 75 sec