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: In how many seconds will a train 100 meters long pass an oak tree, if the speed of the train is 36 km/hr?

 Option A: 6

 Option B: 8

 Option C: 10

 Option D: 12

 Option E: 14
[EX A]: Option C

[EX Q]: Question: Two pipes A and B can separately fill a cistern in 10 and 15 minutes respectively. A person opens both the pipes together when the cistern should have been was full he finds the waste pipe open. He then closes the waste pipe and in another 4 minutes the cistern was full. In what time can the waste pipe empty the cistern when fill?

 Option A: 7

 Option B: 9

 Option C: 5

 Option D: 4

 Option E: 8
[EX A]: Option E

[EX Q]: Question: A train 280 m long, running with a speed of 63 km/hr will pass a tree in?

 Option A: 11

 Option B: 16

 Option C: 188

 Option D: 199

 Option E: 12
[EX A]:
Option B