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.

[EX Q]: Question: A train 175 m long pass a telegraph pole in 5 seconds. Find the speed of the train

 Option A: 66 km/hr

 Option B: 68.4 km/hr

 Option C: 72 km/hr

 Option D: 126 km/hr

 Option E: None
[EX A]: Option D

[EX Q]: Question: Two stations A and B are 20 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?

 Option A: 9

 Option B: 10

 Option C: 11

 Option D: 12

 Option E: 8
[EX A]: Option E

[EX Q]: Question: In a box, there are 7 red, 3 blue and 5 green balls. One ball is picked up randomly. What is the probability that it is neither blue nor green?

 Option A: 2/3

 Option B: 8/21

 Option C: 3/7

 Option D: 7/15

 Option E: 10/21
[EX A]:
Option D