question: 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
answer: Stream of consciousness: D = 600 + 170 = 770
S = 50 * 5/18 = 14 mps
T = 770/14 = 55 se The answer is (C).

q: SHOW TIMER STATISTICS
To apply for the position of photographer at a local magazine, Veronica needs to include three or four of her pictures in an envelope accompanying her application. If she has pre-selected five photos representative of her work, how many choices does she have to provide the photos for the magazine?
Options:
(A) 5
(B) 10
(C) 12
(D) 15
(E) 50
a: Stream of consciousness: Veronica can choose 3 photos in 5C3 = 10 ways
She can choose 4 photos in 5C4 = 5 ways
Total number of ways = 10 + 5 = 15 The answer is (D).

question: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 4 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 60 gallons
(B) 100 gallons
(C) 120 gallons
(D) 160 gallons
(E) 130 gallons
answer: Stream of consciousness: Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 4 gallonsVolume of whole = 4 * 40 = 160 gallons. The answer is (D).

q: Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 5 days?
Options:
(A) 5/18
(B) 1/6
(C) 1/4
(D) 1/9
(E) 2/6
a: Stream of consciousness: A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 5 days = 5 (1/18) = 5/18. The answer is (A).

question: A train running at the speed of 90 km/hr crosses a pole in 12 seconds. Find the length of the train?
Options:
(A) 150
(B) 872
(C) 287
(D) 288
(E) 300
answer: Stream of consciousness: Speed = 90*(5/18) m/sec = 75/3 m/sec
Length of Train (Distance) = Speed * Time
(75/3) * 12 = 300 meter The answer is (E).

question: The average of seven numbers is 18. The average of first three numbers is 14 and the average of last three numbers is 23. What is the middle number?
Options:
(A) 25
(B) 27
(C) 15
(D) 32
(E) 34
answer:
Stream of consciousness: The total of seven numbers = 7X18 = 126
The total of first 3 and last 3 numbers is = 3 X 14+3 X 23 = 111
So, the middle number is (126 - 111 ) = 15 The answer is (C).