AAPL wrote:Princeton Review
How many people contributed to Charity Y?
1) The average contribution to Charity Y was $100.
2) Charity Y collected a total of $47,000 in contributions.
Target question: How many people contributed to Charity Y?
Statement 1: The average contribution to Charity Y was $100.
Clearly NOT SUFFICIENT
Statement 2: Charity Y collected a total of $47,000 in contributions.
Clearly NOT SUFFICIENT
Statements 1 and 2 combined
KEY CONCEPT: average contribution = (total amount of contributions)/(total number of people who contributed)
Let T = total number of people who contributed to Charity Y
Plug in other values to get: $100 = $47,000/T
Multiply both sides by T to get: 100T = 47,000
Divide both sides by 100 to get:
T = 47,000/100 = 470
The answer to the target question is
470 people contributed to Charity Y
Since we can answer the
target question with certainty, the combined statements are SUFFICIENT
Answer: C
Cheers,
Brent
