q: If the average (arithmetic mean) of the four numbers K, 2K + 3, 3K 5 and 5K + 1 is 41, what is the value of K?
Options:
(A) 41
(B) 15 3/4
(C) 22
(D) 23
(E) 25 3/10
a: Stream of consciousness: K + 2K +3 + 3K - 5 + 5K +1 = 11K -1
(11K -1)/4 = 41
11K = 41 * 4 +1 = 164 +1 = 165
K = 165 / 11 = 15. The answer is (A).

question: A train running at the speed of 60 km/hr crosses a pole in 9 sec. What is the length of the train?
Options:
(A) 356
(B) 278
(C) 127
(D) 279
(E) 150
answer: Stream of consciousness: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 9 = 150 m The answer is (E).

q: The average age of a class of 42 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
Options:
(A) 30 Years
(B) 31 Years
(C) 32 Years
(D) 34 Years
(E) 59 Years
a: Stream of consciousness: Total age of students is 42X16 = 672 Years
Total age inclusive of teacher = 43X (16+1) = 731
So, Teacher's age is 731-672 = 59 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(43X1) = 59 Years The answer is (E).

question: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 3446
(B) 2345
(C) 5467
(D) 4767
(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: An equity analyst needs to select 4 stocks for the upcoming year and rank these securities in terms of their investment potential. If the analyst has narrowed down the list of potential stocks to 8, in how many ways can she choose and rank her top 4 picks?
Options:
(A) 1200
(B) 1680
(C) 2102
(D) 4020
(E) 1840
a: Stream of consciousness: Number of ways of choosing 4 stocks = 8C4
Number of ways of ranking the chosen stocks = 4!
Hence total ways of chosing and ranking = 8C4 * 4! = 1680 The answer is (B).

q: Find the third proportional to 9 and 12?
Options:
(A) 10
(B) 12
(C) 16
(D) 19
(E) 20
a:
Stream of consciousness: Formula = Third proportional = (b b)/a
A = 9 and B = 12
(12 12)/ 9 = 144/9 = 16 The answer is (C).