question: Which of the options is a two-digit number, which has a unit's digit that exceeds its ten's digit by 6 and the product of the given number and the sum of its digits is equal to 136.
Options:
(A) 82
(B) 93
(C) 39
(D) 28
(E) 17
answer: Stream of consciousness: Using the elimination method the option that fits this description is 17
7-1 = 3 (unit's digit that exceeds its ten's digit by 3)
17*8 = 136 (the product of the given number and the sum of its digits is equal to 175) The answer is (E).
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question: A man rows his boat 80 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 1 kmph
(B) 6 kmph
(C) 5 kmph
(D) 8 kmph
(E) 7 kmph
answer: Stream of consciousness: Speed downstream = d/t = 80/(2 1/2) = 32 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (32 - 18)/2 = 7 kmph The answer is (E).
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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: Guna has 8 flavors of ice cream in him parlor. How many options are there for Thilak to pick a one-flavor, two-flavor, three-flavor, four-flavor, five-flavor, six-flavor,seven-flavor or eight-flavor order?
Options:
(A) 223
(B) 395
(C) 448
(D) 774
(E) 835
answer:
Stream of consciousness: 8C1 + 8C2+ 8C3+8C4+8C5+8C6+8C7+8C8 = 395. The answer is (B).
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