[GMAT math practice question]
The cost, c and the revenue, r are related via the equation c =ar+b. By how much is the cost increased if the revenue is increased by $10?
1) a=0.5
2) b=5
The cost, c and the revenue, r are related via the equation
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Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.
The first step of the VA (Variable Approach) method is to modify the original condition and the question, and then recheck the question.
The equation c = ar + b tells us that the cost is increases by $a when the revenue is increases by $1.
It follows that the cost is increases by $10a when the revenue is increases by $10. So, the question is asking for the value of a.
The answer is A.
Answer: A
Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.
The first step of the VA (Variable Approach) method is to modify the original condition and the question, and then recheck the question.
The equation c = ar + b tells us that the cost is increases by $a when the revenue is increases by $1.
It follows that the cost is increases by $10a when the revenue is increases by $10. So, the question is asking for the value of a.
The answer is A.
Answer: A
![Image](https://www.mathrevolution.com/img/common/logo.gif)
Math Revolution
The World's Most "Complete" GMAT Math Course!
Score an excellent Q49-51 just like 70% of our students.
[Free] Full on-demand course (7 days) - 100 hours of video lessons, 490 lesson topics, and 2,000 questions.
[Course] Starting $79 for on-demand and $60 for tutoring per hour and $390 only for Live Online.
Email to : [email protected]