question: If six persons sit in a row, then the probability that three particular persons are always together is ?
Options:
(A) 1/6
(B) 1/0
(C) 1/5
(D) 1/4
(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).


q: The average of nine numbers is 15. The average of first four numbers is 11 and the average of last four numbers is 14. What is the middle number?
Options:
(A) 19
(B) 20
(C) 35
(D) 31
(E) 27
a: Stream of consciousness: The total of nine numbers = 9X15 = 135
The total of first 4 and last 4 numbers is = 4 X 11+4 X 14 = 100
So, the middle number is (135 - 100 ) = 35 The answer is (C).


question: In a school of 850 boys, 44% of Muslims, 28% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
Options:
(A) 277
(B) 267
(C) 153
(D) 188
(E) 151
answer: Stream of consciousness: 44 + 28 + 10 = 82%
100 – 82 = 18%
850 * 18/100 = 153 The answer is (C).


q: 30 pens and 75 pencils were purchased for 570. If the average price of a pencil was 2.00, find the average price of a pen.
Options:
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14
a: Stream of consciousness: Since average price of a pencil = 2
∴ Price of 75 pencils = 150
∴ Price of 30 pens = (570 – 150) = 360
∴ Average price of a pen = 420⁄60 = 14 The answer is (E).


question: The speed of a boat in still water is 60kmph and the speed of the current is 40kmph. Find the speed downstream and upstream?
Options:
(A) kmph
(B) kmph
(C) kmph
(D) kmph
(E) kmph
answer: Stream of consciousness: Speed downstream = 60 +40 = 100 kmph
Speed upstream = 60 - 40 = 20 kmph The answer is (D).


question: If O is the center of the circle in the figure above and the area of the unshaded sector is 5, what is the area of the shaded region?
Options:
(A) 25/√π
(B) 30/√π
(C) 20
(D) twenty five (25) 
(E) 30
answer:
Stream of consciousness: 60/360 = 1/6
1/6 of total area = 5
5/6 of total area = 5*5 = 25 The answer is (D).