Joke Collection Website - Public benefit messages - The company's engineering department *** has 20 employees. How many minutes can it take to notify each employee?

The company's engineering department *** has 20 employees. How many minutes can it take to notify each employee?

At least 5 minutes.

1 minute----1 person

2 minutes----3 people

3 minutes----7 people

< p>4 minutes----15 people

5 minutes----31 people

Every time he notified an employee, he asked the employee to also notify other people, and asked others People also notify the next group. As shown above, after 1 minute, A (1 person) was notified, and after 2 minutes, A notified B, and at the same time, C was notified, so after 2 minutes, 3 people, A, B, and C, were actually notified. And so on. Only 15 people were notified after 4 minutes, so it will take at least 5 minutes.