question: What will come in place of the x in the following number series? 12, 26, 54, 110, 222, x
Options:
(A) 444
(B) 446
(C) 448
(D) 452
(E) 454
answer: Stream of consciousness: 12
12 2 + 2 = 26
26 2 + 2 = 54
54 2 + 2 = 110
110 2 + 2 = 222
222 2 + 2 = 446 The answer is (B).

q: If 85 percent of the test takers taking an old paper and pencil GMAT exam answered the first question on a given math section correctly, and 80 percent of the test takers answered the second question correctly, and 5 percent of the test takers answered neither question correctly, what percent answered both correctly?
Options:
(A) 60 %
(B) 65 %
(C) 70%
(D) 75%
(E) 80%
a: Stream of consciousness: {Total} = {First correctly} + {Second correctly} - {Both correctly} + {Neither correctly}
100 = 85 + 80 - {Both correctly} + 5
{Both correctly} = 70. The answer is (C).

question: If the personal income tax rate is lowered from 45% to 30%, what is the differential savings for a tax payer having an annual income before tax to the tune of $48000?
Options:
(A) $3500
(B) $5000
(C) $3150
(D) $7200
(E) $10000
answer: Stream of consciousness: Saving = (45-30)% of 48000 = 7200. The answer is (D).

q: A family with 1 mother, 1 father, and 2 children sit in a car with 2 front seats and 3 back seats. If the mother drives with a child in the front, and the father sits in the back center seat with the other two children on either side of him, how many seating arrangements are possible?
Options:
(A) 2
(B) 4
(C) 6
(D) 8
(E) 10
a: Stream of consciousness: Mother has a fixed place and father, so there are 2! ways to arrange the children, hence The answer is (A).

question: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 120 gallons
(B) 200 gallons
(C) 170 gallons
(D) 180 gallons
(E) 250 gallons
answer: Stream of consciousness: Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 3 gallonsVolume of whole = 3 * 40 = 120 gallons. The answer is (A).

question: How many terminating zeroes R does 200! have?
Options:
(A) 40
(B) 48
(C) 49
(D) 55
(E) 64
answer:
Stream of consciousness: You have 40 multiples of 5, 8 of 25 and 1 of 125. This will give 49 zeros. The answer is (C).