SOLUTION: Some bank robbers leave town, speeding at 70 mph. Ten minutes later, the police give chase, traveling at 78 mph. How long will it take the police to overtake the bank robbers?
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Question 901153: Some bank robbers leave town, speeding at 70 mph. Ten minutes later, the police give chase, traveling at 78 mph. How long will it take the police to overtake the bank robbers? Found 2 solutions by lwsshak3, josmiceli:Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! Some bank robbers leave town, speeding at 70 mph. Ten minutes later, the police give chase, traveling at 78 mph. How long will it take the police to overtake the bank robbers?
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10 min=1/6 hr
let x=travel time of police
x+1/6=travel time of robbers
distance=travel time*speed (same for police and robbers)
78x=70(x+1/6)
78x=70x+70/6
8x=70/6
x=1.46
How long will it take the police to overtake the bank robbers? 1.46 hrs
You can put this solution on YOUR website! Ten minutes is hr
The robber's head start is: mi
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Start a stopwatch when the police leave
Let = time in hours for police
to catch robbers
Let = distance in miles police travel
until they catch robbers
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Bank robber's equation:
(1)
Police equation:
(2)
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Substitute (2) into (1)
(1)
(1)
(1) hrs
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The police catch the robbers in 1 hr 27 min 30 sec
check:
(2)
(2)
(2)
and
(1)
(1)
(1)
OK
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