Question 590097
Two mechanics worked on a car. The first mechanic worked for 20 hours, and the second mechanic worked for 15 hours. Together they charged a total of $3950 . What was the rate charged per hour by each mechanic if the sum of the two rates was 225 per hour? 
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Equations:
r1 + r2 = 225
20r1 + 15r2 = 3950
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Multiply thru 1st equation by 20 to get:
20r1 + 20r2 = 20*225
20r1 + 15r2 = 3950
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Subtract and solve for r2:
5r2 = 550
r2 = 110
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Solve for "r1":
r1 + r2 = 225
r1 + 110 = 225
r1 = 115
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Cheers,
Stan H.