gmatbusters wrote:

What is the cost of fencing the triangular field PQR?

(1) The sides PQ and PR are in ratio 10:9 while the cost of fencing along the PQ & PR is 760$ at the rate of 20$ per meter?

(2) The angle PQR = 60 deg.

OA will be provided tomorrow.

To calculate the cost, we need to know the length of the perimeter and the cost per unit length.

We'll look for statements that give us this information, a Logical approach.

(1) This gives us information on the lengths of 2 of the 3 sides of the triangle.

Insufficient!

(2) This does not give us the information we need.

Insufficient!

Combined: (2) gives us the angle in front of PR and (1) tells us that PQ is larger than PR.

That is, we have a Side-Side-Angle pattern (PR-PQ-PQR) where the 'middle' side is longer than the 'outer' one (PQ>PR)

There are 2 triangles that fulfill the given conditions so we cannot calculate the perimeter.

(E) is our answer.

**Note: as far as I know, this is out of the scope of standard GMAT material... if you want to see more see the Wikipedia entry on law of sines and skip to the 'ambiguous solution' part

_________________

David

Senior tutor at examPAL

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