question: Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?
Options:
(A) 15
(B) 14
(C) 17
(D) 18
(E) 19
answer: Stream of consciousness: In this alternating repetition series, the random number 21 is interpolated every other number into an otherwise simple addition series that increases by 2, beginning with the number 9. The answer is (A).
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question: If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?
Options:
(A) 3/5
(B) 1/2
(C) 1/5
(D) 1/8
(E) 1/32
answer: Stream of consciousness: On the first three flips, you must get heads. Whats the probability of getting heads ? Its 1/2
So for the first three flips, your probability is (1/2)^3 = 1/8
Now for the last two, you want to get tails only. Whats the prob of getting tails ? Well, its the same as prob of getting a heads, namely, 1/2
For the last two flips, your probability is (1/2)^2 = 1/4
So your overall probability for the event in question is 1/8*1/4 = 1/32 The answer is (E).
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question: In what time a sum of money double itself at 3% per annum simple interest?
Options:
(A) 33 1/9%
(B) 33 1/3%
(C) 332 1/3%
(D) 33 9/3%
(E) 13 1/3%
answer: Stream of consciousness: P = (P*3*R)/100
R = 33 1/3% The answer is (B).
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question: What is the least number should be added to 1056, so the sum of the number is completely divisible by 26?
Options:
(A) 10
(B) 20
(C) 30
(D) 40
(E) 50
answer:
Stream of consciousness: (1056 / 26) gives remainder 16
10 + 16 = 26, So we need to add 10 The answer is (A).
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