Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 04 Jul 2015, 08:41

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A driver traveled 1 mile at t ms/ hour. If the speed is

Author Message
TAGS:
Senior Manager
Joined: 08 Aug 2005
Posts: 251
Followers: 1

Kudos [?]: 19 [0], given: 0

A driver traveled 1 mile at t ms/ hour. If the speed is [#permalink]  05 May 2006, 22:13
A driver traveled 1 mile at t ms/ hour. If the speed is t+20ms/hour, it will take 4 minutes less. What Â¡s the value of t?
VP
Joined: 29 Dec 2005
Posts: 1348
Followers: 7

Kudos [?]: 37 [0], given: 0

Re: value of t? [#permalink]  25 May 2006, 18:03
getzgetzu wrote:
A driver traveled 1 mile at t ms/ hour. If the speed is t+20ms/hour, it will take 4 minutes less. What Â¡s the value of t?

good one but little unclear............

t = 10 miles.
VP
Joined: 07 Nov 2005
Posts: 1132
Location: India
Followers: 3

Kudos [?]: 30 [0], given: 1

Yes got t=10 miles as well.

(1/t)-(1/(t+20))=4/60...

=> t^2+20t-300=0

=> t=10
SVP
Joined: 30 Mar 2006
Posts: 1737
Followers: 1

Kudos [?]: 46 [0], given: 0

T=10

1/t -4/60 = 1/t+20

=> 20/t(t+20) = 1/15
=> t^2 +20t -300 = 0

Solving the equation T= -30 or 10
hence speed is 10
Director
Joined: 10 Oct 2005
Posts: 531
Location: US
Followers: 1

Kudos [?]: 17 [0], given: 0

Such problems require you find an equitable equition for time or distance.
In this case it is time which can compared using common variable t.
Similar topics Replies Last post
Similar
Topics:
When the wind speed is 9 miles per hour, the wind-chill 1 09 Nov 2008, 06:45
It takes the high-speed train x hours to travel the z miles 5 04 Oct 2008, 06:08
The time it took car A to travel 400 miles was 2 hours less 2 22 Nov 2006, 23:57
During a 40 mile trip, Malra traveled at an avg. speed of x 1 21 Oct 2006, 09:36
In a 12 mile river, a boat travels up at a speed of s+2, 3 20 Mar 2006, 17:07
Display posts from previous: Sort by