Q: The average of 11 results is 50, if the average of first six results is 49 and that of the last six is 52. Find the sixth result?
Options:
(A) 46
(B) 56
(C) 66
(D) 76
(E) 74
A: OK... Stream of consciousness: 1 to 11 = 11 * 50 = 550
1 to 6 = 6 * 49 = 294
6 to 11 = 6 * 52 = 312
6th = 294 + 312 550 = 56
The answer is (B).

Q: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 2450
(B) 2560
(C) 2650
(D) 3500
(E) 5184
A: OK... 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).

Q: he population of a city is 150,000. If it increases at the rate of 6% per annum, then what will be its population 2 years hence?
Options:
(A) 1697787
(B) 1697723
(C) 168540
(D) 169728
(E) 169718
A: OK... Stream of consciousness: Population after n years = P [1 + (R/100)]2
Population after 2 years = 150000 * [1 + 6/100]2 = (150000 x 53/50 x 53/50) = 168540
The answer is (C).

Q: A batsman makes a score of 87 runs in the 17th inning and thus increases his average by 3. Find his average after 17th inning?
Options:
(A) 39
(B) 88
(C) 3
(D) 7
(E) 62
A:
OK... Stream of consciousness: Let the average after 7th inning = x
Then average after 16th inning = x - 3
\inline
n_jvn herefore 16(x-3)+87 = 17x
\inline
n_jvn herefore x = 87 - 48 = 39
The answer is (A).