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

Redeem

DENOMINATOR AND MILES

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 71
Joined: Sun May 18, 2008 11:04 pm
Thanked: 1 times

DENOMINATOR AND MILES

by charmaine » Sat Oct 18, 2008 9:27 pm
. A certain fraction is equivalent to . If the numerator of the fraction is increased by 4 and the denominator is doubled, the new fraction is equivalent to . What is the sum of the numerator and denominator of the original fraction?
(A) 49 (B) 35 (C) 28
(D) 26 (E) 21
ans. E
A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27


[spoiler]ans. B[spoiler][/spoiler


thaNKS U GUYS [/spoiler]
Top
Source: — Problem Solving |
User avatar
Community Manager
Posts: 1049
Joined: Sun Apr 06, 2008 5:15 pm
Location: Pittsburgh, PA
Thanked: 113 times
Followed by:27 members
GMAT Score:710

Re: DENOMINATOR AND MILES

by dmateer25 » Sun Oct 19, 2008 5:05 am
A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27


[spoiler]ans. B[spoiler][/spoiler

Let X = City MPG
Let X+6 = Highway MPG


462 Miles / x+6 MPG

336 Miles / x MPG

You can set the two equal because a tankful in the car will have an equal number of gallons.

336/x = 462/(x+6)

336x + 2016 = 462X

2016 = 126x

16 = x
Top
User avatar
Community Manager
Posts: 1049
Joined: Sun Apr 06, 2008 5:15 pm
Location: Pittsburgh, PA
Thanked: 113 times
Followed by:27 members
GMAT Score:710

Re: DENOMINATOR AND MILES

by dmateer25 » Sun Oct 19, 2008 5:16 am
charmaine wrote:. A certain fraction is equivalent to . If the numerator of the fraction is increased by 4 and the denominator is doubled, the new fraction is equivalent to . What is the sum of the numerator and denominator of the original fraction?
(A) 49 (B) 35 (C) 28
(D) 26 (E) 21
ans. E

A/B = 2/5

(A+4)/2B= 1/3


2B = 5A
-2B =-3A - 12
_____________
0 = 2A -12
12 = 2A
A =6

Plug 6 back in to get B.

2B = 5(6)
2B = 30
B = 15

A + B = Sum of numerator and denominator
6 + 15 = 21
Top
Post new topic Post Reply
• Page 1 of 1