q: How much is 40% of 60 is greater than 4/5 of 25?
Options:
(A) 2
(B) 5
(C) 12
(D) 8
(E) 4
a: (40/100) * 60 (4/5) * 25
24 - 20 = 4 The answer is (E).
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q: A pipe can fill a cistern in 14 minutes whereas the cistern when fill can be emptied by a leak in 28 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17
(B) 16
(C) 28
(D) 13
(E) 12
a: 1/14 - 1/28 = 1/28
28 minutes The answer is (C).
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q: Which of the following numbers is divisible by 12?
Options:
(A) 1332
(B) 1021
(C) 3221
(D) 4211
(E) 3233
a: 1332. This is the only option with last two digits divisible by 12 The answer is (A).
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q: If x>0, y>0, and |x| > |y|, which of the following must be true?
Options:
(A) x > y
(B) y^2 > x^2
(C) x^3 > y^2
(D) x < y
(E) x < y
a:
Correct Answer: (E)
Let's go through each answer choice: (A) can never be true, since no negative is greater than a positive. (B) doesn't have to be true consider what would happen if x = -2 and y = 1. (C) can never be true, as x^3 must be negative, and y^2 must be positive. (D) can never be true, since if x < 0, -x is the same thing as |x|, and |x| > y. (E) can be manipulated by multiplying both sides by -1, which gives us x > y. Remember that x < 0, so x = |x|, and y is positive, so |y| = y. Thus x > y is the same statement as |x| > |y|, and (A) must be true. The answer is (A).
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