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Question 129722: At the auto repair shop, Mrs. Tennyson was given an estimate of most $225 to repair her car. This estimate included $60 an hour for labor and $75 for parts. What is the maximum number of hours that the mechanic expected to spend on the job?
Second Problem:
Rory has $10 consisting of quarters, dimes, and nickels. If he has 10 more dimes than quarters and twice as many nickels as quarters, how many of each coin does he have?
Third Problelm :
Two planes flying in opposite directions left Newark Airport at the same time. One plane was traveling 420 miles per hour and the other was traveling 516 miles per hour. In how many hours will the planes be 4,680 miles apart?
* Please I need these problems by tonight 9:30 pm as soon as possible please i dont understand them and they are duye tomorrow please email me the answers at 9:30 pm tonight sharp!!!!!!!!!! Thank You
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! At the auto repair shop, Mrs. Tennyson was given an estimate of most $225 to repair her car. This estimate included $60 an hour for labor and $75 for parts. What is the maximum number of hours that the mechanic expected to spend on the job?
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EQUATION:
Let "x" be hours spent on car.
75+60x <= 225
60x <= 150
x <= 2.5 hours
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Second Problem:
Rory has $10 consisting of quarters, dimes, and nickels. If he has 10 more dimes than quarters and twice as many nickels as quarters, how many of each coin does he have?
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Let # of quarters be "x" ; value is 25x cents
# of dimes = "x+10" ; value is 10(x+10)= 10x+100 cents
# of nickels is "2x" ; value is 5(2x) = 10x cents
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EQUATION:
value + value + value = 1000 cents
25x + 10x+100+ 10x = 1000
45x = 900
x = 20 (# of quarters)
x+10= 30 (# of dimes)
2x = 40 (# of nickels)
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Third Problelm :
Two planes flying in opposite directions left Newark Airport at the same time. One plane was traveling 420 miles per hour and the other was traveling 516 miles per hour. In how many hours will the planes be 4,680 miles apart?
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1st plane DATA:
Rate = 420 mph ; Time = x hrs. ; Distance = rt = 420x miles
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2nd plane DATA:
Rate = 516 mph : Time = x hrs. ; Distance = rt = 516xmiles
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EQUATION:
distance + distace = 4680 miles
420x + 516x = 4680
936x = 4680
x = 5 hours
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Cheers,
Stan H.
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