Question 409797: Two rainstorms occurred in one week in a certain area. In the first storm, 30mL of rain fell per hour, and in the second storm, 15mL of rain fell per hour. Rain lasted for a total of 60 hours, resulting in a total rainfall of 1425mL . How long was each storm?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Two rainstorms occurred in one week in a certain area. In the first storm, 30mL of rain fell per hour, and in the second storm, 15mL of rain fell per hour. Rain lasted for a total of 60 hours, resulting in a total rainfall of 1425mL . How long was each storm?
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1st storm DATA:
rate = 30mL/hr ; amt. of rain = x mL ; time = amt/rate = x/30 hr.
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2nd storm DATA:
rate = 15mL/hr ; amt of rain = 1425-x mL ; time = (1425-x)/15 hr.
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Equation:
time + time = 60 hrs.
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x/30 + (1425-x)/15 = 60
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x + 2*1425- 2x = 30*60
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-x = -1050
x = 1050mL
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x/30 = 35 hrs (time of 1st storm)
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(1425-x)/15 = 375/15 = 25 hr (time of 2nd storm)
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Cheers,
Stan H.
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