question: If n is an integer, then the least possible value of |15 - 8n| is?
Options:
(A) 0
(B) 2
(C) 1
(D) 3
(E) 5
answer: Stream of consciousness: |15 - 8n| represents the distance between 15 and 8n on the number line. Now, the distance will be minimized when 8n, which is multiple of 8, is closest to 15. Multiple of 8 which is closest to 15 is 16 (for n = 2), so the least distance is 1: |15 - 16| = 1. The answer is (C).

q: You have found a mutant algae that doubles in size every hour. It takes 18 hours for one algae plant to take up half of a certain lake.
How long would it take for two of these plants to take up half of the same lake?
Options:
(A) 7
(B) 17
(C) 27
(D) 37
(E) 47
a: Stream of consciousness: At 17 hours the one plant will take up 1/4 of the lake (1/2 of 1/2). At 17 hours the two plants would be double the size of the one plant and double 1/4 is one half. The answer is (B).

question: 10 books are placed at random in a shelf. The probability that a pair of books will always be together is?
Options:
(A) 1/6
(B) 1/7
(C) 1/5
(D) 1/9
(E) 1/2
answer: Stream of consciousness: 10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5 The answer is (C).

q: Scott's average (arithmetic mean) golf score on his first four rounds was 18.What score does he need on his fifth round to drop his average score by 2 points?
Options:
(A) 68
(B) 72
(C) 8
(D) 88
(E) 312
a: Stream of consciousness: Average score for first 4 rounds = 18
Average score after 5 rounds = 16
Score Scott needs on his 5th round to drop average score by 2 points = 18 - (2*5) = 8 The answer is (C).

question: A password of a computer consists of five digits 1 through 6. What is the probability that all digits are divisible by 3 ?
Options:
(A) 1/3
(B) 1/6
(C) 1/27
(D) 1/243
(E) 1/486
answer: Stream of consciousness: For each digit there are six possibilities. Two of them (3 and 6) are divisible by three, so there is a one in three chance for each digit, and since the digits are independent of each other, overall probability is 1 / 3^5 or The answer is (D).

question: Right triangle ABC is the base of the prism in the figure above. If AB=AC=2 and the height of the prism is 3, what is the volume of the prism?
Options:
(A) 1
(B) 3/2
(C) 2
(D) 3
(E) 6
answer:
Stream of consciousness: Volume of prism = Area of base * height = 1/2* (square root of 2) * (square root of 2)*3 = 3 The answer is (D).