question: A train 175 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 22 sec
(B) 16 sec
(C) 17 sec
(D) 88 sec
(E) 10 sec
answer: Stream of consciousness: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 175 * 2/35 = 10 sec The answer is (E).

q: A train 260 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40 sec
(B) 50 sec
(C) 32 sec
(D) 49 sec
(E) 60 sec
a: Stream of consciousness: Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 260 + 140 = 400 m
Required time = 400 * 2/25 = 32 se The answer is (C).

question: What is the sum of the 1st 5 prime numbers greater than 20?
Options:
(A) 121
(B) 151
(C) 168
(D) 164
(E) 161
answer: Stream of consciousness: Required sum = (23 + 29 + 31 + 37 + 41) = 161
Note: 1 is not a prime number The answer is (E).

q: An equity analyst needs to select 2 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 5, in how many ways can she choose and rank her top 2 picks?
Options:
(A) 20
(B) 30
(C) 10
(D) 40
(E) 80
a: Stream of consciousness: Number of ways of choosing 2 stocks = 5C2
Number of ways of ranking the chosen stocks = 2!
Hence total ways of chosing and ranking = 5C2 * 2! = 20 The answer is (A).

question: Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?
Options:
(A) 25200
(B) 2543
(C) 2344
(D) 233445
(E) 52757
answer: Stream of consciousness: Number of ways of selecting (3 consonants out of 7) and (2 vowels out of 4) = (7C3 x 4C2) = ( 7 x 6 x 5 x 4 x 3 ) 3 x 2 x 1 2 x 1 = 210. Number of groups, each having 3 consonants and 2 vowels = 210. Each group contains 5 letters. Number of ways of arranging 5 letters among themselves = 5! = 5 x 4 x 3 x 2 x 1 = 120. Required number of ways = (210 x 120) = 25200. The answer is (A).

question: A number is 101102103104...150. As 101 102 103 103.... 150. What is reminder when divided by 3?
Options:
(A) 2
(B) 5
(C) 6
(D) 7
(E) 8
answer:
Stream of consciousness: Divisibility rule for 3 also same as 9. so from the above discussion sum of the digits = 380 and remainder = 380/3 = 2. The answer is (A).