If you talking about the IQ tests that you have too do to access a computer then the second test, which is in the incident room of episode 5 goes like this.

Part 1: 26-17-20-11-14-5-?.

Every number,going from left to right goes down by 6 and it is actually two of these sequences put into one. Let me elaborate; 26-20-14 is one, the other is 17-11-5 and there put together with one each number from the two sequence alternating and going down by 6 every time. This means that the answer (the "?") is the next number from the 26-20-14 sequence which is 8.

Part 2: Z-X-V-T-?

It is going in a sequence of skipping every letter after it in the alphabet and is also going backwards. So Z past Y to X, X skips W to V, and V skips U to T. Which means the answer is R since T skips S to R.

Part 3: "GOD is to DOG as 394 is to ?".

GOD spelt backwards is DOG. So if GOD is to DOG (as in it's backwards) as 394 is to ? then the answer is 493 since its 394 backwards.