question: You have a flashlight that takes 2 working batteries. You have 8 batteries but only 4 of them work.
What is the fewest number of pairs you need to test to guarantee you can get the flashlight on?
Options:
(A) 5
(B) 8
(C) 7
(D) 6
(E) 4
answer: Stream of consciousness: If you break the batteries into 3 groups: Two groups of 3 and one group of 2. By doing this you guarantee that one of the groups has 2 working batteries. Both of the groups of 3 have 3 possible combinations of 2 batteries and the group of 2 only has 1 combination. So, 3 + 3 + 1 = 7 tries at most to find two working batteries. The answer is (C).

q: Divide Rs.32000 in the ratio 3:3?
Options:
(A) 12000, 20000
(B) 12000, 200098
(C) 16000, 16000
(D) 12000, 20006
(E) 12000, 20001
a: Stream of consciousness: 3/6 * 32000 = 16000
5/6 * 32000 = 16000 The answer is (C).

question: Two trains are moving at 80 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 4 sec
(B) 5 sec
(C) 6 sec
(D) 7 sec
(E) 8 sec
answer: Stream of consciousness: 70 + 80 = 150 * 5/18 = 125/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/125 = 6 se The answer is (C).

q: Calculate the largest 3 digit number which is exactly divisible by 89?
Options:
(A) 911
(B) 969
(C) 979
(D) 977
(E) 971
a: Stream of consciousness: Largest 4 digit number is 999
After doing 999 89 we get remainder 20
Hence largest 3 digit number exactly divisible by 89 = 999 - 20 = 979 The answer is (C).

question: If soundharya rows 49 km upstream and 77 km down steam taking 7 hours each, then the speed of the stream
Options:
(A) 6 kmph
(B) 5 kmph
(C) 2 kmph
(D) 3 kmph
(E) 4 kmph
answer: Stream of consciousness: Speed upstream = 49/7 = 7 kmph
Speed down stream = 77/7 = 11kmph
Speed of stream = (11-7) = 2 kmph The answer is (C).

question: A shipment of 8 TV sets contains 1 black and white sets and 7 color sets. If 2 TV sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black and white set?
Options:
(A) 1/7
(B) 1/4
(C) 5/14
(D) 11/28
(E) 13/28
answer:
Stream of consciousness: 7/8 * 6/7 = 3/4
1-(3/4) = 1/4 The answer is (B).