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.

[Q]: Question: Two trains start simultaneously from opposite ends of a 160-km route and travel toward each other on parallel tracks. Train X, traveling at a constant rate, completes the 160-km trip in 5 hours. Train Y, travelling at a constant rate, completes the 160-km trip in 3 hours. How many kilometers had Train X traveled when it met Train Y?

 Option A: 56

 Option B: 58

 Option C: 60

 Option D: 62

 Option E: 64
[A]: Option C


[Q]: Question: The toll for crossing a certain bridge is $0.75 each crossing. Drivers who frequently use the bridge may instead purchase a sticker each month for $13 and then pay only $0.10 each crossing during that month. If a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day, what is the least value of x for which this driver can save money by using the sticker?

 Option A: 12

 Option B: 15

 Option C: 16

 Option D: 28

 Option E: 29
[A]: Option A


[Q]: Question: The owner of a local jewelry store hired two watchmen to guard his diamonds, but a thief still got in and stole some diamonds. On the way out, the thief met each watchman, one at a time. To each he gave 1/2 of the diamonds he had then, and 2 more besides. He escaped with two diamonds. How many did he steal originally?

 Option A: 20

 Option B: 36

 Option C: 25

 Option D: None of these

 Option E: Cannot be determined
[A]:
Option A