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

[Q]: Question: The average age of 15 students of a class is 15 years. Out of these, the average age of 4 students is 14 years and that of the other 10 students is 16 years, The age of the 15th student is

Option A: 11

Option B: 12

Option C: 9

Option D: 14

Option E: 15
[A]: Option C

[Q]: Question: There are 324,437 chicks in a farm. Jack wants to distribute these evenly across 9 different retail shops, how many chicks would remain with him.

Option A: 1 chicks

Option B: 2 chicks

Option C: 3 chicks

Option D: 4 chicks

Option E: 5 chicks
[A]:
Option E