q: A train 600 meters long is running with a speed of 50 kmph. The time taken by it to cross a tunnel 170 meters long is?
Options:
(A) 287 sec
(B) 288 sec
(C) 55 sec
(D) 16 sec
(E) 17 sec
a: Stream of consciousness: D = 600 + 170 = 770
S = 50 * 5/18 = 14 mps
T = 770/14 = 55 se The answer is (C).

question: List K consists of 14 consecutive integers. If -4 is the least integer in list K, what is the range of the positive integers in list K?
Options:
(A) 5
(B) 6
(C) 7
(D) 8
(E) 12
answer: Stream of consciousness: Answer = D = 8
If least = -4, then largest = 9
Range = 9 - 1 = 8 The answer is (D).

q: A class consists of 100 students, 25 of them are girls and 75 boys; 20 of them are rich and remaining poor; 30 of them are fair complexioned. The probability of selecting a fair complexioned rich girl is
Options:
(A) 3/200
(B) 1/59
(C) 1/56
(D) 1/54
(E) 1/53
a: Stream of consciousness: The probability of selecting girl is: 25/100 = 1/4
The probability of selecting rich is: 20/100 = 1/5
The probability of selecting fair complexioned is: 30/100 = 3/10
Three are independent;probability of rich and fair complexioned girl is:
(1/4) (1/5) (3/10) = 3/200 The answer is (A).

question: For some integer m, m^2 - 5 is divisible by all of the following EXCEPT
Options:
(A) 38
(B) 41
(C) 30
(D) 31
(E) 29
answer: Stream of consciousness: Hint: m^2-5 (m is an integer) is never multiple of 3 (try to prove this), hence 30 is out. The answer is (C).

q: A women purchased 3 towels @ Rs.100 each, 5 towels @ Rs.150 each and two towels at a certain rate which is now slipped off from his memory. But she remembers that the average price of the towels was Rs.150. Find the unknown rate of two towels?
Options:
(A) 400
(B) 450
(C) 500
(D) 550
(E) 600
a: Stream of consciousness: 10 * 150 = 1500
3 * 100 + 5 * 150 = 1050
1500 1050 = 450 The answer is (B).

q: The average of seven numbers is 21. The average of first three numbers is 19 and the average of last three numbers is 23. What is the middle number?
Options:
(A) 20
(B) 22
(C) 18
(D) 19
(E) 21
a:
Stream of consciousness: The total of seven numbers = 7X21 = 147
The total of first 3 and last 3 numbers is = 3 X 19+3 X 23 = 126
So, the middle number is (147 - 126 ) = 21 The answer is (E).