question: Select Odd number:
6, 9, 15, 21, 24, 28, 30
Options:
(A) 20
(B) 21
(C) 24
(D) 28
(E) 30
answer: Stream of consciousness: Each of the numbers except 28, is a multiple of 3. The answer is (D).

q: Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 7 1/9
(B) 7 1/8
(C) 7 1/3
(D) 7 1/2
(E) 7 1/1
a: Stream of consciousness: 70 + 50 = 120 * 5/18 = 100/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/100 = 15/2 = 7 1/2 sec The answer is (D).

question: Find the odd man out
36, 315, 612, 810, 966, 1362
Options:
(A) 966
(B) 612
(C) 315
(D) 36
(E) 1362
answer: Stream of consciousness: 315is divisible by 3 which is odd number where as all others are even numbers divisible by 3. The answer is (C).

q: The average of 11 results is 50, if the average of first five results is 49 and that of the last seven is 52. Find the fifth result?
Options:
(A) 55
(B) 56
(C) 57
(D) 58
(E) 59
a: Stream of consciousness: 1 to 11 = 11 * 50 = 550
1 to 5 = 5 * 49 = 245
5 to 11 = 7 * 52 = 364
5th = 245 + 364 550 = 59 The answer is (E).

question: The speed of a boat in still water is 60kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 35, 25 kmph
(B) 80, 40 kmph
(C) 40, 60 kmph
(D) 50, 55 kmph
(E) 50, 65 kmph
answer: Stream of consciousness: Speed downstream = 60 + 20 = 80 kmph
Speed upstream = 60 - 20 = 40 kmph The answer is (B).

question: 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
answer:
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).