Answer: 3,650 days
Explanation:
In the Gregorian Calendar, a common year has 365 days. We are going to assume that a common year always has 365 days for the purposes of this problem.
If one day is 20 minutes, then let us multiply that by 365 days, giving us 7,300 minutes in 1 year. Let us then multiply 7,300 minutes by 10 years. That gives us 73,000 minutes. We know that (based on this problem) there are 20 minutes in 1 day, so we divide 73,000 minutes by 20 minutes. The final answer is 3,650 days.