AAPL wrote:GMAT Paper Tests
A citrus grower receives $15 for each crate of oranges shipped and $18 for each crate of grapefruit shipped. How many crates of oranges did the grower ship last week?
1) Last week the number of crates of oranges that the grower shipped was 20 more than twice the number of crates of grapefruit shipped.
2) Last week the grower received a total of $38,700 from the crates of oranges and grapefruit shipped.
OA C
Target question: How many crates of oranges did the grower ship last week?
Let R = # of crates of oranges shipped last week
Let G = # of crates of grapefruit shipped last week
Our goal is to determine the value of R
Statement 1: Last week the number of crates of oranges that the grower shipped was 20 more than twice the number of crates of grapefruit shipped.
We can write:
R = G + 20
There are infinitely many values of R and G that satisfy statement 1. Here are two:
Case a: R = 21 and G = 1, in which case
21 crates of oranges were shipped
Case b: R = 22 and G = 2, in which case
22 crates of oranges were shipped
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: Last week the grower received a total of $38,700 from the crates of oranges and grapefruit shipped
We can write:
15R + 18G = 38,700
There are MANY possible solutions to this equation.
So, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
Statement 1 tells us that
R = G + 20
Statement 2 tells us that
15R + 18G = 38,700
Since we COULD solve this system for R and G, we COULD determine
the number of crates of oranges sold. Of course, we're not going to waste our time solving the system, since our sole objective is to determine whether we have sufficient information to answer the
target question with certainty (which we do!)
Since we can answer the
target question with certainty, the combined statements are SUFFICIENT
Answer: C
Cheers,
Brent
