Bunuel wrote:
How many people received a certain survey?
(1) Six-tenths of those who received the survey responded.
(2) Of those who received the survey, 42 responded.
Target question: How many people received a certain survey? Statement 1: 6/10 of those who received the survey responded. This statement is clearly insufficient to answer the
target question with certainty
Statement 1 is NOT SUFFICIENT
Statement 2: Of those who received the survey, 42 responded.This statement is clearly insufficient to answer the
target question with certainty
Statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined Let
T = the total number of people who received the survey
From the information in statement 1, we can write: The number of people who responded to the survey =
(6/10)TSince statement to tells us that 42 people responded to the survey, we can write:
(6/10)T = 42
At this point, we need only recognize that we COULD solve this equation for T, which means we COULD answer the
target question with certainty
As such, the combined statements are SUFFICIENT
Answer: C
ASIDE: Let's solve the equation "for fun"
Take:
(6/10)T = 42
Multiply both sides of the equation by 10 to get: 6T = 420
Divide both sides by 6 to get: T = 70
This means that 70 received the survey
Answer: C
Cheers,
Brent
_________________
Brent Hanneson – Creator of gmatprepnow.com
I’ve spent the last 20 years helping students overcome their difficulties with GMAT math, and the biggest thing I’ve learned is…
Many students fail to maximize their quant scores NOT because they lack the skills to solve certain questions but because they don’t understand what the GMAT is truly testing -
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