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: 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: Johnson has a corporate proposal. The probability that vice-president Adams will approve the proposal is 0.7. The probability that vice-president Baker will approve the proposal is 0.4. The probability that vice-president Corfu will approve the proposal is 0.4. The approvals of the three VPs are entirely independent of one another.
Suppose the Johnson must get VP Adam's approval, as well as the approval of at least one of the other VPs, Baker or Corfu, to win funding. What is the probability that Johnson's proposal is funded?

Option A: 0.49

Option B: 0.6

Option C: 0.448

Option D: 0.5

Option E: 0.52

Answer: Option C

Question: Question: What two-digit number is less than the sum of the square of its digits by 15 and exceeds their doubled product by 5?

Option A: 95

Option B: 99

Option C: 26

Option D: 73

Option E: None of the Above

Answer:
Option D