Rationale: 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).
The answer: (D)
Question: 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
Reasoning: Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62
Ans: (E)
Question: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 2354
(B) 2644
(C) 2645
(D) 4577
(E) 5184
Rationale: Largest 4 digit number is 9999
After doing 9999 88 we get remainder 55
Hence largest 4 digit number exactly divisible by 88 = 9999 - 55 = 9944
The answer: (C)
Question: Find the largest 4 digit number which isexactly divisible by 88?
Options:
(A) 7890
(B) 8900
(C) 9944
(D) 9976
(E) 10000
Reasoning: If x = 2 then f(x) = 8/15 and f(1/x) = -8/15 which is equal to -f(x)
Ans: (A)
Question: If f(x) = x^3/(x^4 - 1), what is f(1/x) in terms of f(x)?
Options:
(A) -f(x)
(B) f(x)
(C) 2*f(x)
(D) 1/f(x)
(E) 2/f(x)
Rationale: P(at last 1 tails) = 1 - P(all heads) = 1 - (1/2)^3 = 7/8.
The answer: (D)
Question: The probability is 1/2 that a certain coin will turn up heads on any given toss. If the coin is to be tossed three times, what is the probability that on at least one of the tosses the coin will turn up tails?
Options:
(A) 1/8
(B) 1/2
(C) 3/4
(D) 7/8
(E) 15/16
Rationale: Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62
The answer: (E)
Question: Find the value of y from given equation: (12)^3 x 6^4 432 = y?
Options:
(A) 2345
(B) 2790
(C) 3490
(D) 7389
(E) 5184