q: Find the average of the first 41 natural numbers?
Options:
(A) 8
(B) 9
(C) 10
(D) 11
(E) 21
a: Stream of consciousness: Average of the first 'n' natural numbers = (n + 1)/2
We get (41 + 1)/2 = 21 The answer is (E).

question: A racng car travels k kilometres in n hours. How many miles will it travel in x hours at the same rate?
Options:
(A) knx
(B) kn
(C) knx
(D) kx
(E) kxn
answer: Stream of consciousness: Given Speed = k/n
To Find distance in x hours with same speed
Distance = speed * time
Distance = k/n*x = kx/n The answer is (E).

q: A can do a job in 18 days and B can do it in 24 days. A and B working together will finish twice the amount of work in days?
Options:
(A) 22 1/6
(B) 22 1/2
(C) 20 4/7
(D) 22 1/9
(E) 22 1/1
a: Stream of consciousness: 1/18 + 1/24 = 7/72
72/7 = 72/7 *2 = 20 4/7 days The answer is (C).

question: Two pipes A and B can fill a cistern in 37 minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
Options:
(A) 9 minutes
(B) 7
(C) 6
(D) 5
(E) 4
answer: Stream of consciousness: Let B be turned off after x minutes. Then, Part filled by (A + B) in x min. + Part filled by A in (30 -x) min. = 1. x(2/75 + 1/45) + (30 - x). 2/75 = 1 11x/225 + (60 - 2x)/75 = 1 11x + 180 - 6x = 225. x = 9. The answer is (A).

q: There are 3 teams each with 6 basket players. How many combinations are there if we were to pick 2 players from the 3 teams such that no team was picked twice?
Options:
(A) 50
(B) 23
(C) 108
(D) 28
(E) 45
a: Stream of consciousness: There are altogether three arrangements, which are we can select two members each from team A and B, each from team A and C, and each from team B and C. For each arrangement, there are altogether 36 possibilities (6*6) since each team has 6 players. So there are a total of 108 possibilities (36*3). I hope this method is easier for you to understand. The answer is (C).

q: A man purchased 3 blankets @ Rs.100 each, 5 blankets @ Rs.150 each and two blankets at a certain rate which is now slipped off from his memory. But he remembers that the average price of the blankets was Rs.150. Find the unknown rate of two blankets?
Options:
(A) Rs 420
(B) Rs 550
(C) Rs 490
(D) Rs 450
(E) Rs 457
a:
Stream of consciousness: 10 * 150 = 1500
3 * 100 + 5 * 150 = 1050
1500 1050 = 450 The answer is (D).