2007 AMC 12B Problems/Problem 2

From AoPSWiki

The following problem is from both the 2007 AMC 12B #2 and 2007 AMC 10B #3, so both problems redirect to this page.

Problem

A college student drove his compact car 120 miles home for the weekend and averaged 30 miles per gallon. On the return trip the student drove his parents' SUV and averaged only 20 miles per gallon. What was the average gas mileage, in miles per gallon, for the round trip?

$\mathrm {(A)} 22$ $\mathrm {(B)} 24$ $\mathrm {(C)} 25$ $\mathrm {(D)} 26$ $\mathrm {(E)} 28$

Solution

The trip was 240 miles, and $\dfrac{120}{30}+\dfrac{120}{20}=4+6=10$ gallons. Therefore, the average milage was $\dfrac{240}{10}=24 \Rightarrow \mathrm {(B)}$ miles per gallon.

2007 AMC 12B (Problems • Resources)
Preceded by Problem 1	Followed by Problem 3
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25

Personal tools

Navigation

Search

Toolbox

2007 AMC 12B Problems/Problem 2

From AoPSWiki

Problem

Solution

See Also