I will take a stab. I am positive 1 is correct. I am pretty sure about 2 and 3.
1) E
REASONING: Both statements tell you the same thing: that QPR is 30 degrees. To find PQR, you need either PRQ or PRS. Neither can be deduced from the information given.
A way to verify this is to think of two situations that yield different answers for PQR, but that satisfy the statements given.
Situation 1: RPS measures 40 degrees, PRS measures 50 degrees. This gives PRQ = 130 degrees. Statement 1 tells us that QPR = 30, giving us PQR = 20 degrees. Statement 2 tells us that PQR and PRQ sum to 150. This is verified (130 + 20)
Situation 2: RPS measures 30 degrees, PRS measures 60 degrees. Both statements are again verified. QPR is 30. PQR = 20, PRQ = 130. They sum to 150.
Thus, the information given is NOT sufficient.
2) E
REASONING: Again, think of situations that don't violate the assumptions, but give different results for the quantity asked.
Statement 1 alone: not sufficient. It tells us that no balls are white and even. We could have 0 white balls and 0 even balls, which gives us P(white or even) = 0. We could also have 10 white odd balls and 10 red even balls, which gives us P(white or even) = .8.
Statement 2 alone: not sufficient. It tells us that the different between P(white) and P(even) is .2. Let's say all 15 balls are white, and 10 are even. P(white) - P(even) = .6 - .4 = .2 and P(white or even) = 1. Let's say we have 10 white balls and 5 even balls. P(white) - P(even) = .4 - .2 = .2. P(white or even) = .6.
If we combine the two statements, it tells us that in statement 2, we can't have any balls that are white and even. This doesn't affect the question: P(white or even) is still different under the different scenarios. Thus, we need more information to deduce P(white or even).
3. D
REASONING: For n to be a multiple of 5, p or q must be 5. Therefore, in p^2 X p^2, one of the terms MUST be 25, so D must be a multiple of 25.