q: In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much? Look at this series: 120, 30, 240, 25, ___, 20, 480, 15... Which number is missing?
Options:
(A) 120
(B) 360
(C) 340
(D) 960
(E) 280
a: Stream of consciousness: B 360
This is an alternating addition and subtraction series. In the first pattern, 120 is added to each number to arrive at the next. In the second, 5 is subtracted from each number to arrive at the next. The answer is (B).

question: From a group of 7 men and 6 women, five persons are to be selected to form a committee so that at least 3 men are there on the committee. In how many ways can it be done?
Options:
(A) 624
(B) 702
(C) 756
(D) 812
(E) 832
answer: Stream of consciousness: Total men are 7
Total women are 6 so we select 5 peoples in both and at least 3 are men
7c3*6c2+7c4*6c1+7c5*6c0 then we get the 756 The answer is (C).

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) 19 1/7 min
(B) 15 1/7 min
(C) 17 1/7 min
(D) 7 1/7 min
(E) 7 2/7 min
a: Stream of consciousness: 1/20 + 1/30 - 1/40 = 7/120
120/7 = 17 1/7 The answer is (C).

question: A person travels at a speed of 10 mph from one city to another. However while returning as there was not much traffic. He came with a speed of 15mph. what is his average speed?
Options:
(A) 10Kmph
(B) 11Kmph
(C) 12Kmph
(D) 13Kmph
(E) 14Kmph
answer: Stream of consciousness: Average speed = 2xy/(x+y) = (2*15*10)/25 = 12Kmph The answer is (C).

q: The average length of the sides of triangle ABC is 12. What is the perimeter of triangle ABC?
Options:
(A) 4
(B) 6
(C) 12
(D) 24
(E) 36
a: Stream of consciousness: (average) = (perimeter)/3;
12 = (perimeter)/3;
(perimeter) = 36. The answer is (E).

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 = c/c = 1/126 The answer is (E).