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: A boat takes 19 hours for travelling downstream from point A to point B and coming back to a point C midway between A and B. If the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph, what is the distance between A and B ?

 Option A: 160 km

 Option B: 180 km

 Option C: 200 km

 Option D: 220 km

 Option E: None

Answer: Option B


Question: Question: One-tenth of the students at a nursery school are 4 years old or older. If 20 students have not yet reached their third birthday, and a total of 50 students are not between 3 years old and 4 years old, how many children are in the nursery school?

 Option A: 150

 Option B: 300

 Option C: 450

 Option D: 490

 Option E: 620

Answer: Option B


Question: Question: If 10 and 15 are the lengths of two sides of a triangular region, which of the following can be the length of the third side?
I. 10
II. 15
III. 25

 Option A: I only

 Option B: II only

 Option C: I and II only

 Option D: II and III only

 Option E: I, II, and III

Answer:
Option C