question: Find the odd man out
253, 136, 352, 324, 631, 244
Options:
(A) 324
(B) 136
(C) 352
(D) 631
(E) 531
answer: Stream of consciousness: The sum all three digits comes to 10 except 324 The answer is (A).

q: The average of five results is 46 and that of the first four is 45. The fifth result is?
Options:
(A) 22
(B) 02
(C) 78
(D) 50
(E) 18
a: Stream of consciousness: 5 * 46 4 * 45 = 50 The answer is (D).

question: People standing in a straight line are wearing alternating colored shirts. The pattern of shirts begins with red, followed by green, blue, and yellow. This pattern continues (red, green, blue, and yellow) until it ends with a red shirt. If there are more than 4 people in line, which of the following cannot be the number of people in the line?
Options:
(A) 17
(B) 37
(C) 49
(D) 61
(E) 72
answer: Stream of consciousness: The correct answer should not take the form: 4x + 1. Hence, it is The answer is (E).

q: There are 9 cities numbered 1 to 9.From how many cities the flight can start so as to reach the city 8 either directly or indirectly such that the path formed is divisible by 3.
Options:
(A) 7
(B) 8
(C) 9
(D) 10
(E) 11
a: Stream of consciousness: Start from 1: 1368, Start from 2: 2358, Start from 3: 378, Start from 4: 48, Start from 5: 528, Start from 6: 678, Start from 7: 78, Why start from 8???, Start from 9: 918. So flights can start from all 8 other cities. The answer is (B).

question: If six persons sit in a row, then the probability that three particular persons are always together is ?
Options:
(A) 1/3
(B) 1/9
(C) 1/5
(D) 1/7
(E) 1/1
answer: Stream of consciousness: 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).

question: Twelve coins are tossed simultaneously. In how many of the outcomes will the third coin turn up a head?
Options:
(A) 2^9
(B) 2^11
(C) 3 * 2^8
(D) 3 * 2^9
(E) 3 * 2^10
answer:
Stream of consciousness: Fix the third coin as H. The remaining 11 coins have 2^11 outcomes. The answer is (B).