question: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 6 kmph
(B) 5 kmph
(C) 2 kmph
(D) 8 kmph
(E) 1 kmph
answer: Stream of consciousness: Speed downstream = d/t = 85/(2 1/2) = 34 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (34 - 18)/2 = 8 kmph The answer is (D).
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question: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 2234
(B) 4350
(C) 4560
(D) 5132
(E) 5184
answer: Stream of consciousness: Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62 The answer is (E).
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question: What approximate value should come in place of question mark (?) in the following equation
287.532 + 1894.029 657.48 = 843.095 + ?
Options:
(A) 870
(B) 790
(C) 680
(D) 770
(E) 890
answer: Stream of consciousness: ? = 285 + 1895 655 845 or, ? = 680 The answer is (C).
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question: In the expression 51840/x^4, for which of the following values of x will the expression NOT be an integer?
Options:
(A) 1/2
(B) 1
(C) 2
(D) 3
(E) 5
answer:
Stream of consciousness: We can straightaway eliminate A & B, since the expression will always yields an integer for those values
Out of C, D, and E. Let us consider option E. 51840 has only one trailing zero and tens digit is not 5, so It has just one 5 in it. But for the expression to be an integer numerator should have 5^4. The answer is (E).
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