7528:5306::4673:?
Options:
(A) 2351
(B) 2451
(C) 2551
(D) 2651
(E) 2751
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As there is a difference of 2222. 7528-2222 = 5306. so 4673-2222 = 2451 So the answer is: (B).
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The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Options:
(A) 87
(B) 15
(C) 17
(D) 19
(E) 16
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Average of 20 numbers = 0
Sum of 20 numbers = (0 * 20) = 0
It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (-a). So the answer is: (D).
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If y is the smallest positive integer such that 3,150 multiplied by y is the square of an integer, then y must be
Options:
(A) 2
(B) 5
(C) 6
(D) 7
(E) 14
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3150*y = A^2
3 * 1050 * y = A^2
3*5*210*y = A^2
3*5*7*3*2*5*y = A^2
2*3^2*5^2*7*y = A^2
Concept: The factors of squared integer should occur in pair. So, the only numbers left are 2*7
Hence 14 ; So the answer is: (E).
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