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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Find the odd man out 4, 5, 15, 49, 201, 1011, 6073
Options:
(A) 10
(B) 7
(C) 5
(D) 2
(E) 3
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4 x 1 + 2 = 6
6 x 2 + 3 = 15
15 x 3 + 4 = 49
49 x 4 + 5 = 210 So the answer is: (C).
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The average of first 15 natural numbers is?
Options:
(A) 7
(B) 8
(C) 9
(D) 10
(E) 11
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Sum of 15 natural no. = 240/2 = 120
Average = 120/15 = 8 So the answer is: (B).
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