BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Race

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pm
Location: Gandhinagar
Thanked: 41 times
Followed by:2 members

Race

by shashank.ism » Mon Feb 08, 2010 7:20 am
In a 4000 meter race around a circular stadium having a circumference of 1000 meters, the fastest runner and the slowest runner reach the same point at the end of the 5th minute, for the first time after the start of the race. All the runners have the same starting point and each runner maintains a uniform speed throughout the race. If the fastest runner runs at twice the speed of the slowest runner, what is the time taken by the fastest runner to finish the race?

a) 20 min
b) 15 min
c) 10 min
d) 5 min
e) 4 min
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 am
Location: India
Thanked: 64 times
Followed by:6 members
GMAT Score:760

by harsh.champ » Mon Feb 08, 2010 7:29 am
shashank.ism wrote:In a 4000 meter race around a circular stadium having a circumference of 1000 meters, the fastest runner and the slowest runner reach the same point at the end of the 5th minute, for the first time after the start of the race. All the runners have the same starting point and each runner maintains a uniform speed throughout the race. If the fastest runner runs at twice the speed of the slowest runner, what is the time taken by the fastest runner to finish the race?

a) 20 min
b) 15 min
c) 10 min
d) 5 min
e) 4 min
Imp. pt. to be kept in the mind:-The fastest runner is leading by a whole circumference at the 5th minute.
So,relative speed = F(fastest)-S(slowest)
relative time = 5min. = 300 seconds
relative distance = 1000
also,F=2S
Hence,by solving 2S - S = 1000/5 = 200 (metres/min.)

TIME TAKEN TO FINISH THE RACE =[spoiler] 4000 / 400 = 10 min. C[/spoiler]
Last edited by harsh.champ on Mon Feb 08, 2010 11:06 am, edited 2 times in total.
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P
Top
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pm
Location: Arabian Sea
Thanked: 125 times
Followed by:2 members

by ajith » Mon Feb 08, 2010 10:49 am
shashank.ism wrote:In a 4000 meter race around a circular stadium having a circumference of 1000 meters, the fastest runner and the slowest runner reach the same point at the end of the 5th minute, for the first time after the start of the race. All the runners have the same starting point and each runner maintains a uniform speed throughout the race. If the fastest runner runs at twice the speed of the slowest runner, what is the time taken by the fastest runner to finish the race?

a) 20 min
b) 15 min
c) 10 min
d) 5 min
e) 4 min
Fastest runner has double the speed of slowest and they meet at the end of 5 mins

The difference in distance covered btw fastest and slowest = 1 lap when they meet
Since the speed of fastest is double of slowest he must have run two laps by that time

Time required for him to finish the race = 5+5 = 10 minutes
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Post new topic Post Reply
• Page 1 of 1