q: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 3456
(B) 4567
(C) 4789
(D) 5678
(E) 5184
a: OK... 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: On average, the bottle-nosed dolphin comes up for air once every three minutes; the beluga whale, a close relative, comes up for air on average once every six minutes. The number of times a bottle-nosed dolphin would come up for air in a 24 hour period is approximately what percent greater than the number of times a beluga whale would come up for air in that same period?
Options:
(A) 25%
(B) 50%
(C) 75%
(D) 100%
(E) 150%
a: OK... Dolphin once in 3 min;
Beluga once in 6 min;
So, dolphin comes up 2 times frequently than beluga, which is 150% (6-3)/2*100.
The answer is (E).

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) 21
(B) 56
(C) 18
(D) 25
(E) 23
a:
OK... 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).