question: The speed of a train is 90 kmph. What is the distance covered by it in 30 minutes?
Options:
(A) 15
(B) 66
(C) 77
(D) 52
(E) 45
answer: Stream of consciousness: 90 * 30/60 = 45 kmph The answer is (E).

q: Fifteen coins are tossed simultaneously. In how many of the outcomes will the third coin turn up a head?
Options:
(A) 2^9
(B) 2^14
(C) 3 * 2^8
(D) 3 * 2^9
(E) 3 * 2^10
a: Stream of consciousness: Fix the third coin as H. The remaining 14 coins have 2^14 outcomes. The answer is (B).

question: Three 6 faced dice are thrown together. The probability that exactly two dice show the same number on them is
Options:
(A) 5/54
(B) 5/12
(C) 5/17
(D) 5/18
(E) 5/14
answer: Stream of consciousness: Using question number 11 and 12, we get the probability as
1 - (1/36 + 5/9) = 5/12 The answer is (B).

q: The average of five results is 48 and that of the first four is 45. The fifth result is?
Options:
(A) 50
(B) 60
(C) 70
(D) 80
(E) 90
a: Stream of consciousness: 5 * 48 4 * 45 = 60 The answer is (B).

question: Find the average of the first 9 natural numbers?
Options:
(A) 8
(B) 5
(C) 10
(D) 11
(E) 12
answer: Stream of consciousness: Average of the first 'n' natural numbers = (n + 1)/2
We get (9 + 1)/2 = 5 The answer is (B).

question: In what time will a bus 200 m long cross in the road, if its speed be 72 km/hr?
Options:
(A) 15
(B) 20
(C) 14
(D) 10
(E) 12
answer:
Stream of consciousness: Speed = 72 * 5/18 = 20 m/sec
Time taken = 200/20 = 10 sec. The answer is (D).