question: Two trains are traveling on parallel tracks in the same direction. The faster train travels at 130 miles per hour, while the slower train travels at 100 miles per hour. At 3 o'clock the faster train is 15 miles behind the slower one. How far apart are the two trains at 5 o'clock?
Options:
(A) 45 miles
(B) 80 miles
(C) 90 miles
(D) 120 miles
(E) 400 miles
answer: Stream of consciousness: Answer = A. 45 miles
Relational speed = 130 - 100 = 30 miles per hour
In 2 hours, difference = 30 * 2 = 60 miles
Fast train trailing 15 miles, so effective difference = 60 - 15 = 45 miles The answer is (A).
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question: How much is 80% of 40 is greater than 4/5 of 25?
Options:
(A) 17
(B) 19
(C) 11
(D) 12
(E) 10
answer: Stream of consciousness: (80/100) * 40 (4/5) * 25
32 - 20 = 12 The answer is (D).
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question: How many seconds will a train 140 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 28 sec
(B) 29 sec
(C) 24 sec
(D) 25 sec
(E) 26 sec
answer: Stream of consciousness: D = 140 + 150 = 290
S = 36 * 5/18 = 10 mps
T = 290/10 = 29 sec The answer is (B).
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question: The average of ten numbers is 210. The average of first five numbers is 40 and the average of last four numbers is 200. What is the middle number?
Options:
(A) A) 200
(B) B) 2000
(C) C) 800
(D) D) 2100
(E) E) 1100
answer:
Stream of consciousness: The total of ten numbers = 10X210 = 2100
The total of first 5 and last 4 numbers is = 5 X 40+4 X 200 = 1000
So, the middle number is (2100 - 1000 ) = 1100 The answer is (E).
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