question: A man rows his boat 72 km downstream and 30 km upstream, taking 3 hours each time. Find the speed of the stream?
Options:
(A) 6 kmph
(B) 5 kmph
(C) 2 kmph
(D) 8 kmph
(E) 7 kmph
answer: Stream of consciousness: Speed downstream = d/t = 72/(3) = 24 kmph
Speed upstream = d/t = 30/(3) = 10 kmph
The speed of the stream = (24 - 10)/2 = 7 kmph The answer is (E).

q: If six persons sit in a row, then the probability that three particular persons are always together is?
Options:
(A) 1/9
(B) 1/3
(C) 1/5
(D) 1/1
(E) 1/2
a: 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: Dacid obtained 76, 65, 82, 67 and 85 marks (out of 100) in English, Mathematics, Physics, Chemistry and Biology. What are his average marks?
Options:
(A) 75
(B) 45
(C) 23
(D) 28
(E) 96
answer: Stream of consciousness: Average = (76 + 65 + 82 + 67 + 85)/5 = 375/5 = 75. The answer is (A).

q: A family with 1 mother, 1 father, and 4 children sit in a car with 2 front seats and 3 back seats. If the mother drives with a child in the front, and the father sits in the back center seat with the other two children on either side of him, how many seating arrangements are possible?
Options:
(A) 3
(B) 4
(C) 6
(D) 8
(E) 24
a: Stream of consciousness: Mother has a fixed place and father, so there are 4! ways to arrange the children, hence The answer is (E).

question: Look at this series: 8, 43, 11, 41, __, 39, 17, ... What number should fill in the blank?
Options:
(A) 8
(B) 14
(C) 43
(D) 44
(E) 9
answer: Stream of consciousness: Answer: Option B
This is a simple alternating addition and subtraction series. The first series begins with 8 and adds 3; the second begins with 43 and subtracts 2. The answer is (B).

question: The measure of the side of a square is multiplied by 6. If x represents the perimeter of the original square, what is the value of the new perimeter?
Options:
(A) 3x
(B) 4x
(C) 6x
(D) 12x
(E) 27x
answer:
Stream of consciousness: Original perimeter = x
Hence original side = x/4
New side = 6x/4
New perimeter = 4*6x/4 = 6x The answer is (C).