Ques: There is a 100 pound watermelon laying out in the sun. 99 percent of the watermelon's weight is water. After laying out for a few hours 98 percent of the watermelon's weight is water.
How much water evaporated?
Options:
(A) 20
(B) 30
(C) 40
(D) 50
(E) 10
Ans: (D)
CoT: In the beginning it is 99 pounds water and 1 pound other stuff. At the end the 1 pound other stuff is 2 percent so the total weight is 50 pounds. 50 pounds - 1 pound other stuff = 49 pounds water. So 99 pounds - 49 pounds = 50 pounds water lost.

Ques: There are 3 teams each with 5 basket players. How many combinations are there if we were to pick 2 players from the 3 teams such that no team was picked twice?
Options:
(A) 50
(B) 23
(C) 75
(D) 28
(E) 45
Ans: (C)
CoT: There are altogether three arrangements, which are we can select two members each from team A and B, each from team A and C, and each from team B and C. For each arrangement, there are altogether 25 possibilities (5*5) since each team has 5 players. So there are a total of 75 possibilities (25*3).

Ques: Which one of the following is not a prime number?
Options:
(A) 31
(B) 61
(C) 71
(D) 91
(E) 101
Ans: (D)
CoT: 91 is divisible by 7. So, it is not a prime number.

Ques: Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank?
Options:
(A) A16
(B) G4
(C) E4
(D) E3
(E) F2
Ans: (C)

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
CoT: Answer: Option C
The letters decrease by 1; the numbers are multiplied by 2.