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: On flipping 3 coins together what is the outcomes for at least four tail?

 Option A: 1/7

 Option B: 0

 Option C: 1

 Option D: 4/13

 Option E: 5/13

A: Option B
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Q: Question: How much time does a train 150 metres long running at 90 km/hr take to pass a pole?

 Option A: 7.9s

 Option B: 6s

 Option C: 7.5s

 Option D: 7.6s

 Option E: 7.4s

A: Option B
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Q: 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

A:
Option B
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