question: A train running at the speed of 90 km/hr crosses a pole in 10 seconds. Find the length of the train.
Options:
(A) 150
(B) 180
(C) 250
(D) 200
(E) 225
answer: Stream of consciousness: Speed = 90*(5/18) m/sec = 25 m/sec
Length of Train (Distance) = Speed * Time
25 *10 = 250 meter The answer is (C).


q: How many two-digit numbers satisfy this property.: The last digit (unit's digit) of the square of the two-digit number is 2 ?
Options:
(A) 2
(B) 3
(C) 4
(D) 5
(E) 0
a: Stream of consciousness: A number ending with 2 can never be a perfect squar The answer is (E).


question: A motorcyclist goes from Bombay to Pune, a distance of 288 kms at an average of 32 kmph speed. Another man starts from Bombay by car 2 ½ hours after the first, and reaches Pune ½ hour earlier. What is the ratio of the speed of the motorcycle and the car?
Options:
(A) 1:2
(B) 1:5
(C) 1:4
(D) 2:3
(E) 1:8
answer: Stream of consciousness: T = 288/32 = 9 h
T = 9 - 3 = 6
Time Ratio = 9:6 = 3:2
Speed Ratio = 2:3 The answer is (D).


q: 2 persons can finish a job in 8 days. First person alone can finish the work in 24 days. How many days does the second person take to finish the job?
Options:
(A) 10 days
(B) 12 days
(C) 14 days
(D) 16 days
(E) 18 days
a: Stream of consciousness: 2 persons can do work in 1 day = 1/8
First person can do work in 1 day = 1/24
Second person can do work in 1 day = 1/8-1/24 = 1/12
So Second person can finish work in 12 days The answer is (B).


question: There are 20 balls in a box: 11 balls are green, 6 are blue and 3 are white. Then 1 green and 1 blue balls are taken from the box and put away. What is the probability that a green ball is selected at random from the box?
Options:
(A) 1/13
(B) 10/18
(C) 3/13
(D) 5/13
(E) 6/13
answer: Stream of consciousness: If 1 green and 1 blue ball are taken from the box, then there are 10 green, 5 blue and 3 white balls, a total of 18 balls. If one ball is selected at random, the probability that it is green is given by 10 / 18 The answer is (B).


question: Which of the following is a prime number ?
Options:
(A) 90
(B) 94
(C) 96
(D) 97
(E) 98
answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: Clearly, 97 is a prime number. The answer is (D).