Hi,

I don't understand how x can be solved with the given information. The correct answer is C. Please advise. Thanks!

Ladan,

In quad. PQSU, if we know Angle(SQP) (assume a) and Angle(SUP) (assume b) or if we know their sum then X can be calculated, because

we know 90 + a + b + x = 360...(1)

from statement (1) we know Angle RQS = Angle RSQ ( QR=RS) and Angle(RSQ) = 180 -a
from statemtn (2) we know Angle SUT = Angle TSU (ST = UT) and Angle(TSU) = 180 -b

Since RT is a straight line, we know x + 180-a + 180 -b = 180 or x -(a+b) = -180 or (a+b) = x + 180

If you substitute the the value of a+b in (1) X can be calculated.

Hope it helps

GMAT 2007