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by GMATinsight » Mon Jul 21, 2014 11:00 am
abhasjha wrote:Image
Question : Area of Triangular Region PRT = ?

If we drop a perpendicular RX on PT from Point S then we can see that
Image
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Area of triangle PRX = Area of triangle PQR and
Area of triangle RST = Area of triangle RXT

Therefore, Area of Triangle PRT = (1/2) Area of Rectangle PQST

Statement 1) Area of PQST = 24
i.e. Area of Triangle PRT = (1/2)24 = 12
SUFFICIENT

Statement 2) RT = 5
NOT SUFFICIENT

Answer: Option A
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by Brent@GMATPrepNow » Mon Jul 21, 2014 4:05 pm
Image

In the figure shown, what is the area of triangular region PRT?

1) The area of rectangular region PQST is 24
2) The length of line segment RT is 5
Target question: What is the area of triangular region PRT?

Statement 1: The area of rectangular region PQST is 24
The area of ∆PRT = (base)(height)/2
Statement 1 tells us that (base)(height) = 24
Since the base and the height of the rectangle are the SAME as the base and the height of the triangle PRT, we can use this information to find the area of ∆PRT.
The area of ∆PRT = (base)(height)/2 = 24/2 = 12
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: The length of line segment RT is 5
The area of ∆PRT = (base)(height)/2
Statement 2 tells us NOTHING about the base and height, so we can't use this to find the area of ∆PRT.
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Answer = A

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