Q: In a school of 850 boys, 44% of Muslims, 32% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
Options:
(A) A) 125
(B) B) 119
(C) C) 153
(D) D) 721
(E) E) 159
A: OK... Stream of consciousness: 44 + 32 + 10 = 86%
100 84 = 14%
850 * 14/100 = 119
The answer is (B).

Q: There are 1000 doors that are of the open-close type. When a person opens the door he closes it and then opens the other. When the first person goes he opens-closes the doors in the multiples of 1 i.e., he opens and closes all the doors. when the second goes he opens and closes the doors 2, 4 6 8 respectively. Similarly when the third one goes he does this for 3 6 9 12 15th doors respectively. Find number of doors that are open at last.
Options:
(A) 29
(B) 31
(C) 32
(D) 24
(E) 21
A: OK... Stream of consciousness: 31. only the perfect squares between 1 to 1k
The answer is (B).

Q: K-numbers are positive integers with only 2's as their digits. For example, 2, 22, and 222 are K-numbers. The K-weight of a number n is the minimum number of K-numbers that must be added together to equal n. For example, the K-weight of 50 is 5, because 50 = 22 + 22 + 2 + 2 + 2. What is the K-weight of 650?
Options:
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14
A: OK... Stream of consciousness: 650 = 2*222 + (22*9) + 4*2
K weight of 600 = 2 +9+2 = 13
The answer is (D).

Q: Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
Options:
(A) 17 1/4 min
(B) 28 1/7 min
(C) 17 1/7 min
(D) 17 1/8 min
(E) 17 5/7 min
A:
OK... Stream of consciousness: 1/20 + 1/30 - 1/40 = 7/120
120/7 = 17 1/7
The answer is (C).