Stiv wrote:

A rectangular-shaped carpet remnant that measures x feet by y feet is priced at $50. What is the cost of the carpet, in dollars per square yard? (9 square feet = 1 square yard)

1)\(50xy\)

2) \(450xy\)

3) \(\frac {xy}{9}\)

4)\(\frac {xy}{50}\)

5) \(\frac {450}{xy}\)

x feet

y feet

total price = $50

find: cost of carpet ($/yd^2)

now the trap here would be for you to convert x feet and y feet using the given conversion in the question.

see, the conversion states that 9 square feet = 1 yard -->> if you analyze this statement it means square feet! SQUARE! this means that two units have already been multiplied (hope you're catching my drift)

this means that we should multiply x by y first, we have xy (area in square feet; this makes the conversion consistent)

(xy square feet) x (1 square yard)/(9 square feet) = xy square yard / 9 -->> see we want to cancel out square feet in numerator and square feet in denominator

now we want to get the cost of carpet per square yard, this means we just divide the total cost by what we got earlier; we have..

50/(xy/9) = 50 * 9 / xy = 450/xy

Answer is (E)

I think the main takeaway here is the trap that I said earlier. You have to think like the test maker.

That being said, this question is very GMAT-esque, and I'm not surprised since the source is GMATPrep.

Anyway, can I get a kudos?

Thanks!

_________________

Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure... than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat.

- T. Roosevelt