Hi All,

This question is perfect for TESTing THE ANSWERS (we're looking for an answer that divides evenly into 336 AND - when you add 6 to it - evenly divides into 462. How long would it take you to do the necessary division to find that answer?). The "math" approach to this prompt can actually be done in a number of ways, depending on how you want to set up the algebra. Here's another way:

Since a "tankful" of gasoline is the same number of gallons of gas whether driving on the highway or driving in the city, we can use a variation of the Distance Formula to create 2 equations:

462 = H(G) where H = miles/gallon on the highway and G = # of gallons

336 = C(G) where C = miles/gallon in the city and G = # of gallons

Right now, we have 3 variables and 2 equations. The last sentence gives us one more equation to work with: "the car traveled 6 fewer miles per gallon in the city than on the highway." This translates into:

C = H - 6

So now we have a "system" of equations (3 variables and 3 unique equations means that we CAN solve for all 3 variables). We're trying to solve for C…..

462 = H(G)

336 = C(G)

C = H - 6

H = C + 6 plug this into the first equation….

462 = (C+6)(G)

462 = CG + 6G

336 = CG plug this into the prior equation….

462 = 336 + 6G

126 = 6G

21 = G

**REMINDER: This is the value of G. We want the value of C.**

Plug G=21 into 336 = CG

336 = C(21)

16 = C

Final Answer:

GMAT assassins aren't born, they're made,

Rich

_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels

Contact Rich at: Rich.C@empowergmat.com

# Rich Cohen

Co-Founder & GMAT Assassin

Special Offer:

Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee

www.empowergmat.com/
*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****