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 2 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) 60 miles
(B) 80 miles
(C) 75 miles
(D) 120 miles
(E) 400 miles
answer: Stream of consciousness: Answer = C. 75 miles
Relational speed = 130 - 100 = 30 miles per hour
In 3 hours, difference = 30 * 3 = 90 miles
Fast train trailing 15 miles, so effective difference = 90 - 15 = 75 miles The answer is (C).
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question: At a meeting of the 3 Joint Chiefs of Staff, the Chief of Naval Operations does not want to sit next to the Chief of the National Guard Bureau. How many ways can the 3 Chiefs of Staff be seated around a circular table?
Options:
(A) 120
(B) 480
(C) 960
(D) 2520
(E) 5040
answer: Stream of consciousness: Bunuel, I'm also a little confused with the number of arrangements of n distinct objects in a circle. Why is it given by (n-1)!. In theveritasanswer they say:answer C (960), should be the number of ways to arrange all 7 without the seating restriction given. Is this incorrect? The answer is (C).
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question: Solve below question 2x + 1 = -23
Options:
(A) -8
(B) -9
(C) -12
(D) -4
(E) 12
answer: Stream of consciousness: 1. Subtract 1 from both sides: 2x + 1 - 1 = -23 - 1 2. Simplify both sides: 2x = -24 3. Divide both sides by 2: 4. Simplify both sides: x = -12 The answer is (C).
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question: There are different 15 circles. What is the number of the greatest possible points with which the circles intersect?
Options:
(A) 390
(B) 100
(C) 110
(D) 180
(E) 210
answer:
Stream of consciousness: Maximum points of intersection between n different circles = n*(n - 1) = 15*14 = 210 The answer is (E).
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