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.

Input: Consider Input: 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

Output: Option B


Input: Consider Input: Question: A car during its journey travels 30 minutes at a speed of 60 kmph, another 45 minutes at a speed of 80 kmph, and 1 hours at a speed of 70 kmph.The average speed of the car is

 Option A: 63.07 kmph

 Option B: 64 kmph

 Option C: 75 kmph

 Option D: 80 kmph

 Option E: None of these

Output: Option D


Input: Consider Input: Question: A lady bought five books namely A,B,C,D,E to distribute her 7 friends. How many ways she can distribute books?

 Option A: 7^3

 Option B: 7^4

 Option C: 7^5

 Option D: 7^6

 Option E: 7^2


Output: Option C