If Mike buys a bicycle and a helmet for a total cost of $315, how much does the helmet cost?

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Princeton Review

If Mike buys a bicycle and a helmet for a total cost of $315, how much does the helmet cost?

1) The bicycle costs twice as much as the helmet
2) The bicycle costs $210

OA D

[Brent@GMATPrepNow]

Princeton Review

If Mike buys a bicycle and a helmet for a total cost of $315, how much does the helmet cost?

1) The bicycle costs twice as much as the helmet
2) The bicycle costs $210

OA D

Target question: How much does the helmet cost?

Given: bicycle + helmet = $315

Statement 1: The bicycle costs twice as much as the helmet.
Let x = cost of helmet
So, 2x = cost of bicycle
Since the total cost is $315, we can write: x + 2x = 315
Simplify: 3x = 315
Solve: x = 315/3 = 105
So, the answer to the target question is the helmet costs $105
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: The bicycle costs $210.
Since we already know that bicycle + helmet = $315, we can conclude that the helmet costs $105
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent