Q: A box contains nine bulbs out of which 4 are defective. If four bulbs are chosen at random, find the probability that atleast one bulb is good.
Options:
(A) 125/127
(B) 127/125
(C) 125/126
(D) 126/125
(E) 126/127
A: OK... Stream of consciousness: Required probability = 1 - 1/126 = 125/126
The answer is (C).

Q: A train 200 m long running at 80 kmph crosses a platform in 22 sec. What is the length of the platform?
Options:
(A) 338
(B) 277
(C) 350
(D) 288
(E) 271
A: OK... Stream of consciousness: D = 80 * 5/18 = 22 = 488 200 = 288
The answer is (D).

Q: A shopkeeper sells his goods at cost price but uses a weight of 800 gm instead of kilogram weight. What is his profit percentage?
Options:
(A) 25%
(B) 18%
(C) 20%
(D) 40%
(E) 45%
A: OK... Stream of consciousness: 100(1000-800)/800 = 25%
Profit percentage = 25%
The answer is (A).

Q: How many factors does 35^2 have?
Options:
(A) 2
(B) 8
(C) 24
(D) 25
(E) 26
A:
OK... Stream of consciousness: 36^2 = 6*6*6*6 = 2^4*3^4
Total factors = (4+1)*(4+1) = 6*4 = 24
The answer is (C).