question: A train of 24 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 4.5 km long?
Options:
(A) 4
(B) 3
(C) 5
(D) 6
(E) 9
answer: Stream of consciousness: D = 25 * 60 + 4500 = 6000 m
T = 6000/60 * 18/5 = 360 sec = 6 mins The answer is (D).

q: In what time a sum of money double itself at 7% per annum simple interest?
Options:
(A) 33 1/8%
(B) 33 1/3%
(C) 14 2/7%
(D) 33 4/3%
(E) 73 1/3%
a: Stream of consciousness: P = (P*7*R)/100
R = 14 2/7% The answer is (C).

question: A Train requires 10 seconds to pass a pole while it requires 40 seconds to cross a stationary train which is 300 mtrs long. Find the speed of the train.
Options:
(A) 36kmph
(B) 42kmph
(C) 48kmph
(D) 52kmph
(E) 64kmph
answer: Stream of consciousness: In 10s the train crosses the pole and in 40 sec the train crosses one more stationary train
In 30 sec the train travels a distance of 300 mtrs
Speed = 300/30 = 10 m/s = 10 * 18/5 = 36 kmph The answer is (A).

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).

question: At what rate percent on simple interest will a sum of money double itself in 30 years?
Options:
(A) 3 1/3%
(B) 8 1/3%
(C) 3 5/3%
(D) 5 1/3%
(E) 3 1/7%
answer: Stream of consciousness: P = (P*30*R)/100
R = 3 1/3% The answer is (A).

question: John makes $50 a week from his job. He earns a raise and now makes $80 a week. What is the % increase?
Options:
(A) 16%
(B) 16.66%
(C) 17.9%
(D) 18.12%
(E) 60%
answer:
Stream of consciousness: Increase = (30/50)*100 = (3/5)*100 = 60%. The answer is (E).