BlogTalk GMAT Workshop 2: Quantitative Section Part 2 Apply Numbers, Not Variables!

Tip #1: Concrete values (numbers) are easier to work with than variables. Go into Home Depot… Buy : 6 bolts for 30 cents each and 10 light bulbs for 60 cents each Pay: 10 dollars for the tab You get how much change back? Go into Home Depot… Buy: b bolts for c cents each and d light bulbs for e cents each Pay: y dollars for the tab You get how much change back?

Go into Home Depot…

Buy : 6 bolts for 30 cents each and 10 light bulbs for 60 cents each

Pay: 10 dollars for the tab

You get how much change back?

Go into Home Depot…

Buy: b bolts for c cents each and d light bulbs for e cents each

Pay: y dollars for the tab

You get how much change back?

x = h =

Tip # 2: There are several approaches to applying numbers in place of variables in test questions. Replace an explicit variable (e.g. x, y, a, b, c) in a question with a number. Unknown quantity where a % or fraction of its value is taken in the question. Replace the variable/unknown quantity with one of the answer choices in a question.

Replace an explicit variable (e.g. x, y, a, b, c) in a question with a number.

Unknown quantity where a % or fraction of its value is taken in the question.

Replace the variable/unknown quantity with one of the answer choices in a question.

Tip #3: Any combination of these numbers-for-variables approaches can also help solve one question . Problem Solving Question #240 Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 percent fescue. If a mixture of X and Y contains 30 percent ryegrass what percent of the weight of the mixture is X? 10% 33 1/3% 40% 50% 66 2/3%

Problem Solving Question #240

Seed mixture X is 40 percent ryegrass and 60 percent bluegrass by weight; seed mixture Y is 25 percent ryegrass and 75 percent fescue. If a mixture of X and Y contains 30 percent ryegrass what percent of the weight of the mixture is X?

10%

33 1/3%

40%

50%

66 2/3%

Problem Solving Question #220 John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance ? 4y 5y So what we are really trying to 6y find here is x. 8y 9y Tip #4: No matter what, keep in mind what the question is asking you to find.

Problem Solving Question #220

John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance ?

4y

5y So what we are really trying to

6y find here is x.

8y

9y

If you would like to submit questions for the workshop, send an e-mail to [email_address] or fax questions to (775) 637-8573. Check out my blog at www.gmatdoctor.blogspot.com for extra tips and techniques that you can use to greatly improve your score on the GMAT CAT exam OR my radio channel at www.blogtalkradio.com/gmatdoctor for more details on my other radio programs. BLOGTALK GMAT WORKSHOP 2: QUANTITATIVE PART 2