SOLUTION: You can ride a bike at 15 mph. Your sister rides 12 mph. You give her a one-hour head start. In how many hours will you catch up if neither of you stops.
(15 + x) (12 + x)
15x
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(15 + x) (12 + x)
15x
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Question 719654: You can ride a bike at 15 mph. Your sister rides 12 mph. You give her a one-hour head start. In how many hours will you catch up if neither of you stops.
(15 + x) (12 + x)
15x - 12x
In 2 hours Found 2 solutions by stanbon, Alan3354:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! You can ride a bike at 15 mph. Your sister rides 12 mph. You give her a one-hour head start. In how many hours will you catch up if neither of you stops.
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Your DATA:
rate = 15 mph ; time = x hrs ; distance = 15x miles
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Sister DATA:
rate = 12 mph ; time = x+1 hrs ; distance = 12(x+1)
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Equation:
distance = distance
15x = 12x + 12
3x = 12
x = 4 hrs (time to catch up)
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Cheers,
Stan H.
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You can put this solution on YOUR website! You can ride a bike at 15 mph. Your sister rides 12 mph. You give her a one-hour head start. In how many hours will you catch up if neither of you stops.
(15 + x) (12 + x)
15x - 12x
In 2 hours
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In 1 hour, she's 12 miles away (12*1)
You "gain on her" at 3 mi/hr (15-12)
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t = d/r = 12/3 = 4 hours
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