You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
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Question: Question: It takes eight hours for a 600 km journey, if 120 km is done by train and the rest by car. It takes 20 minutes more, if 200 km is done by train and the rest by car. The ratio of the speed of the train to that of the car is?

 Option A: 3:4

 Option B: 7:6

 Option C: 1:4

 Option D: 5:4

 Option E: 2:4

Answer: Option A


Question: Question: If x is positive and y is negative, which of the following must be true?

 Option A: The product of x and y is positive

 Option B: The sum of x and y is positive

 Option C: The sum of x and y is negative

 Option D: The difference of x and y is positive

 Option E: The sum of x^2 and y^2 is positive

Answer: Option E


Question: Question: A runner runs the 40 miles from Marathon to Athens at a constant speed. Halfway through the run she injures her foot, and continues to run at half her previous speed. If the second half takes her 8 hours longer than the first half, how many hours did it take the runner to run the second half?

 Option A: 10

 Option B: 12

 Option C: 16

 Option D: 20

 Option E: 24

Answer:
Option C