What is d?

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What is d?

by Max@Math Revolution » Sun Jul 14, 2019 11:12 pm

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[GMAT math practice question]

What is d?

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1) b = √3
2) c = 2

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by Max@Math Revolution » Wed Jul 17, 2019 12:17 am

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=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

The first step of the VA (Variable Approach) method is to modify the original condition and the question. We then recheck the question. We should simplify conditions if necessary.

Remind that a 30°-60°-90° right triangle has the ration among sides 1:2: √3.

Condition 1)
We know all angles of the triangles, ABC and CDE. Since b = √3, we can find CE =1, c = 2 and BC = √3. It follows that d = BC + CE = √3 + 1.
Thus, condition 1) is sufficient.

Condition 2)
We know all angles of the triangles, ABC and CDE. Since c = 2, we can find CE = 1 and BC = √3. It follows that d = BC + CE = √3 + 1.
Thus, condition 2) is sufficient.

Therefore, D is the answer.
Answer: D