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: 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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Q: Question: In a certain school, the ratio of boys to girls is 5 to 13. If there are 160 more girls than boys, how many boys are there?

 Option A: 100

 Option B: 36

 Option C: 45

 Option D: 72

 Option E: 117

A: Option A
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Q: Question: Tough and Tricky questions: Absolute Values.
If |a| = 1/2 and |b| = 2/3, which of the following CANNOT be the result of a + b?

 Option A: 7/6

 Option B: -1/6

 Option C: 1/6

 Option D: 2/6

 Option E: -7/6

A:
Option D
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