question: In how many different ways can the letters of the word 'CASES' be arranged?
Options:
(A) 250
(B) 280
(C) 60
(D) 310
(E) 360
answer: Stream of consciousness: Number of ways = 5!/2! = 5X4X3X2X1/2X1 = 60 The answer is (C).

q: The average of 13 numbers is 60. Average of the first 7 of them is 56 and that of the last 7 is 61. Find the 8th number?
Options:
(A) 39
(B) 83
(C) 45
(D) 53
(E) 64
a: Stream of consciousness: Sum of all the 13 numbers = 13 * 60 = 780
Sum of the first 7 of them = 7 * 56 = 392
Sum of the last 7 of them = 7 * 61 = 427
So, the 8th number = 427 + 392 - 780 = 39. The answer is (A).

question: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 3456
(B) 4567
(C) 4789
(D) 5678
(E) 5184
answer: 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: There are 6561 balls out of them 1 is heavy.Find the min. no. of times the balls have to be weighed for finding out the haevy ball.
Options:
(A) 7
(B) 8
(C) 9
(D) 10
(E) 11
a: Stream of consciousness: The simple logic is to divide total balls into three sets. Weigh any two sets against each other(these two must contain equal number of balls). From this we can identify which set contains the heavy ball. Divide this set into three and repeat until you find the heavier ball. Under this logic, the minimum number of weighings required turns out to be the smallest integer greater than or equal to log(n), where n is the total number of balls and the base of logarithm is 3. Or simply [log(n)/log(3)] with any base. Here, n = 6561. log 6561 / log 3 = 8 The answer is (B).

question: If x is an even integer and y is an odd integer, which of the following is an even integer?
Options:
(A) x+y
(B) x+2y
(C) 3x+y
(D) x+y^2
(E) x+y+2
answer: Stream of consciousness: Plug in an even integer for x; in this case 2
Plug in an odd integer for y; in this case 1
2+1 = 3 Odd
2+(2*1) = 4 Even
(3*2)+1 = 6 + 1 = 7 Odd
2+(1^2) = 2 + 1 = 3 Odd
2+1+2 = 5 Odd The answer is (B).

question: How much is 25% of 40 is greater than 4/5 of 25?
Options:
(A) 10
(B) 776
(C) 66
(D) 12
(E) 99
answer:
Stream of consciousness: (25/100) * 40 (4/5) * 25
10 - 20 = 10 The answer is (A).