q: A box contains nine bulbs out of which 4 are defective. If four bulbs are chosen at random, find the probability that all the four bulbs are defective.
Options:
(A) 62/63
(B) 125/126
(C) 1/63
(D) 1/42
(E) 1/126
a: Stream of consciousness: Answer: Option E
Out of nine, five are good and four are defective. Required probability = â´câ‚„/â¹câ‚„ = 1/126 The answer is (E).


question: How much time will it take for an amount of 1000 to yield 100 as interest at 5% per annum of simple interest?
Options:
(A) 3 years
(B) 4 years
(C) 2 years
(D) 5 years
(E) 7 years
answer: Stream of consciousness: Time = (100 x 100)/(1000 x 5) years = 2 years. The answer is (C).


q: How many seconds will a train 100 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 22
(B) 28
(C) 25
(D) 77
(E) 88
a: Stream of consciousness: D = 100 + 150 = 250
S = 36 * 5/18 = 10 mps
T = 250/10 = 25 se The answer is (C).


question: The average of 13 numbers is 59. Average of the first 7 of them is 57 and that of the last 7 is 61. Find the 8th number?
Options:
(A) 59
(B) 83
(C) 45
(D) 53
(E) 64
answer: Stream of consciousness: Sum of all the 13 numbers = 13 * 59 = 767
Sum of the first 7 of them = 7 * 57 = 399
Sum of the last 7 of them = 7 * 61 = 427
So, the 8th number = 427 + 399 - 767 = 59. The answer is (A).


q: What least number must be added to the least number of six digits so that the resulting number may be a perfect square.
Options:
(A) 489
(B) 267
(C) 278
(D) 199
(E) 111
a: Stream of consciousness: The least number of six digits = 100000 3 10 00 00 317 9 61 100 61 627 3900 4389 – 489 Least number to be added = 489. The answer is (A).


q: How much 60% of 50 is greater than 50% of 30?
Options:
(A) 18
(B) 91
(C) 11
(D) 17
(E) 15
a:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: (60/100) * 50 – (50/100) * 30
30 - 15 = 15 The answer is (E).