The price of gasoline at a service station increased from $1.65 per gallon last week to $1.82 per gallon this week.

[Gmat_mission]

The price of gasoline at a service station increased from $1.65 per gallon last week to $1.82 per gallon this week. Sally paid $26.40 for gasoline last week at the station. How much more will Sally pay this week at the station for the same amount of gasoline?

A. $1.70

B. $2.55

C. $2.64

D. $2.72

E. $2.90

[spoiler]OA=D[/spoiler]

Source: Official Guide

[JamesHammel]

For every gallon of gas bought, the price at T2 (second week) will be $0.17 more (1.82-1.65).
For every dollar spent, the price at T2 will be 0.17/1.65 more
-> we are essentially finding the percentage increase (\(\frac{p2-p1}{p1}\) ).

The amount spent at T1 = 26.4
=> She would have spent (26.4 * 0.17)/1.65

The question is testing if you can recognise the prime factors of 264 and 165

-> 165 = 3 * 5 * 11

264/3 = 88
88/11 = 8
=> 264/33 = 8
=> 264/16.5 = 16

we are left with 16 * 0.17 = 1.6 + 0.7 + 0.42 = 2.72. The answer is D

[jasminekaur280]

For every gallon of gas bought, the price at T2 (second week) will be $0.17 more (1.82-1.65).
For every dollar spent, the price at T2 will be 0.17/1.65 more
-> we are essentially finding the percentage increase (p2-p1/p1).

The amount spent at T1 = 26.4
=> She would have spent (26.4 * 0.17)/1.65

The question is testing if you can recognise the prime factors of 264 and 165

-> 165 = 3 * 5 * 11

264/3 = 88
88/11 = 8
=> 264/33 = 8
=> 264/16.5 = 16

we are left with 16 * 0.17 = 1.6 + 0.7 + 0.42 = 2.72. The answer is D

[Scott@TargetTestPrep]

The price of gasoline at a service station increased from $1.65 per gallon last week to $1.82 per gallon this week. Sally paid $26.40 for gasoline last week at the station. How much more will Sally pay this week at the station for the same amount of gasoline?

A. $1.70

B. $2.55

C. $2.64

D. $2.72

E. $2.90

[spoiler]OA=D[/spoiler]

Source: Official Guide

Solution:

Since $26.40 bought 26.40/1.65 = 16 gallons last week, and this week she has to pay 1.82 - 1.65 = $0.17 more per gallon, she has to pay 16 x 0.17 = $2.72 more this week for the same amount of gasoline.

Answer: D