Question: Look at this series: 0.25, 1.75, ____, 85.75, 600.25, ... What number should fill the blank?
Options:
(A) 11.25
(B) 12.25
(C) 13.25
(D) 9.25
(E) 10.75
Answer: This is a simple multiplication series. Each number is 7 times greater than the previous number.
The answer is (B).

Question: Jack has two dice, one has six equally probable sides, labeled 1, 2, 3, 4, 5, 6, and the other has seven equally probable sides, labeled 1, 2, 3, 4, 5, 6, 7. If Jack rolls both dice what is the probability that both of the number's sum will be 13?
Options:
(A) 3/14
(B) 2/7
(C) 1/3
(D) 1/42
(E) 12/21
Answer: Both Dice addition result is 13 = (6+7)
Probability that the number on first die is 6 = 1/6
Probability that the number on Second die is 7 = 1/7
Probability that Both Dice addition result is 13 = 1/6 * 1/7 = 1/42
The answer is (D).

Question: The average age of a family of 6 members is 34 years.If the age of the youngest member is 7 years,what was the average age of the family at the birth of the youngest member?
Options:
(A) 15
(B) 18
(C) 21
(D) 12
(E) 27
Answer: Present age of total members = 6 X 34 = 204
7 yrs back their ages were = 6 x 7 = 42
Ages at the birth of youngest member = 204 - 42 = 162
Therefore, avg age at the birth of youngest member = 162/6 = 27.
The answer is (E).

Question: If six persons sit in a row, then the probability that three particular persons are always together is ?
Options:
(A) 1/6
(B) 1/2
(C) 1/5
(D) 1/2
(E) 1/1
Answer:

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
Six persons can be arranged in a row in 6! ways. Treat the three persons to sit together as one unit then there four persons and they can be arranged in 4! ways. Again three persons can be arranged among them selves in 3! ways. Favourable outcomes = 3!4! Required probability = 3!4!/6! = 1/5
The answer is (C).