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Catch up hours dilemma

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Catch up hours dilemma

by success1111 » Tue May 05, 2009 1:35 am
Mary passed a certain gas station on a highway while traveling west at a constant speed of 50 miles per hour. Then, 15 minutes later, Paul passed the same gas station while traveling west at a constant speed of 60 miles per hour. If both drivers maintained their speeds and both remained on the highway for at least 2 hours, how long after he passed the gas station did Paul catch up with Mary?

A. 30 min
B. 45 min
C. 1 hr
D. 1 hr 15 min
E. 1 hr 30 min

I solved this question by this way.

Distance Mary travelled by 15 minutes(catch up distance) is 50 * 15/60 = 12.5 miles

Paul catch up speed is 60-50 = 10.

Hour after Paul would catch up with mary is 12.5/10 = 1 hr 25 minutes.
I was surprised my answer was no there. Am i missing something? Please help
Trust but verify.
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Re: Catch up hours dilemma

by Pranay » Tue May 05, 2009 2:01 am
success1111 wrote:Mary passed a certain gas station on a highway while traveling west at a constant speed of 50 miles per hour. Then, 15 minutes later, Paul passed the same gas station while traveling west at a constant speed of 60 miles per hour. If both drivers maintained their speeds and both remained on the highway for at least 2 hours, how long after he passed the gas station did Paul catch up with Mary?

A. 30 min
B. 45 min
C. 1 hr
D. 1 hr 15 min
E. 1 hr 30 min

I solved this question by this way.

Distance Mary travelled by 15 minutes(catch up distance) is 50 * 15/60 = 12.5 miles

Paul catch up speed is 60-50 = 10.

Hour after Paul would catch up with mary is 12.5/10 = 1 hr 25 minutes.
I was surprised my answer was no there. Am i missing something? Please help

1.25 hrs (as you calculated) is not equivalent to 1 hr 25 mins but it is 1 hr 15 mins. :)
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Senior | Next Rank: 100 Posts
Posts: 87
Joined: Sun Apr 19, 2009 11:07 pm

Re: Catch up hours dilemma

by success1111 » Tue May 05, 2009 2:16 am
Pranay wrote:
success1111 wrote:Mary passed a certain gas station on a highway while traveling west at a constant speed of 50 miles per hour. Then, 15 minutes later, Paul passed the same gas station while traveling west at a constant speed of 60 miles per hour. If both drivers maintained their speeds and both remained on the highway for at least 2 hours, how long after he passed the gas station did Paul catch up with Mary?

A. 30 min
B. 45 min
C. 1 hr
D. 1 hr 15 min
E. 1 hr 30 min

I solved this question by this way.

Distance Mary travelled by 15 minutes(catch up distance) is 50 * 15/60 = 12.5 miles

Paul catch up speed is 60-50 = 10.

Hour after Paul would catch up with mary is 12.5/10 = 1 hr 25 minutes.
I was surprised my answer was no there. Am i missing something? Please help

1.25 hrs (as you calculated) is not equivalent to 1 hr 25 mins but it is 1 hr 15 mins. :)
HAHAHAHAHAHAHAHAHAHAHAHA. Incredible.That is one of my careless mistakes. Thanks a lot
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