Data Sufficiency

swerve wrote: ↑

Sat Aug 07, 2021 8:06 am

Boat World sells a certain boat and a certain trailer. What is the price of the trailer?

1) The price of the boat is $7,500 more than the price of the trailer
2) The combined price of the boat and trailer is $15,000

The OA is C

Source: Magoosh

Let B = the price of the boat
Let T = the price of the trailer

Target question: What is the value of T?

Statement 1: The price of the boat is $7,500 more than the price of the trailer.
We can write: B = T + 7500
Since there is no way to solve this equation for T, statement 1 is NOT SUFFICIENT

Statement 2: The combined price of the boat and trailer is $15,000
We can write: B + T = 15,000
Since there is no way to solve this equation for T, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
From the two statements we get the following system of equations:
B = T + 7500
B + T = 15,000
At this point, we should recognize that we have a system of 2 linear equations with 2 variables. As such, we COULD solve this system for B and T, which means we COULD answer the target question.
ASIDE: Although we COULD solve the system of equations, we would never waste valuable time on test day doing so. We need only determine that we COULD answer the target question.

Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

Cheers,
Brent