# Puzzle | Disclosing Secret

**Problem Statement:** A secret can be told only to 2 persons in 5 minutes. The same person tells to 2 more persons and so on. So How long will take to spread a secret to 768 persons?

**Solution:**

In the beginning, let only 1 person know the secret.

- Now, this 1 person will tell disclose the secret to 2 other persons in 5 mins.
**(Secret known = 2, Remaining = 766 persons)** - Now, this 2 person will tell disclose the secret to 4 other persons in 5 mins.
**(Secret known = 4, Remaining = 764 persons)** - Now, this 4 person will tell disclose the secret to 8 other persons in 5 mins.
**(Secret known = 8, Remaining = 760 persons)** - Now, this 8 person will tell disclose the secret to 16 other persons in 5 mins.
**(Secret known = 16, Remaining = 752 persons)** - Now, this 16 person will tell disclose the secret to 32 other persons in 5 mins.
**(Secret known = 32, Remaining = 736 persons)** - Now, this 32 person will tell disclose the secret to 64 other persons in 5 mins.
**(Secret known = 64, Remaining = 704 persons)** - Now, this 64 person will tell disclose the secret to 128 other persons in 5 mins.
**(Secret known = 128, Remaining = 640 persons)** - Now, this 128 person will tell disclose the secret to 256 other persons in 5 mins.
**(Secret known = 256, Remaining = 512 persons)** - Now, this 256 person will tell disclose the secret to 512 other persons in 5 mins.
**(Secret known = 512, Remaining = 256 persons)** - Now, as only 256 persons are left for the secret to being known, therefore, this 512 person will tell disclose the secret to only 1 person each i.e. 256 other persons in 2.5 mins.
**(Secret known = 768, Remaining = 0 persons)**

**Total time taken = ** 9 * 5 + 1 * 2.5 = 47.5 mins

### Therefore, total time taken to disclose the secret to 768 persons = 47.5 minutes

## Recommended Posts:

- Puzzle 26 | (Know Average Salary without Disclosing Individual Salaries)
- Puzzle | Secret Mail Problem
- Puzzle 51| Cheryl’s Birthday Puzzle and Solution
- Puzzle 15 | (Camel and Banana Puzzle)
- Puzzle 81 | 100 people in a circle with gun puzzle
- Puzzle 34 | (Prisoner and Policeman Puzzle)
- Puzzle 85 | Chain Link Puzzle
- Puzzle | 3 Priests and 3 devils Puzzle
- Puzzle 28 | (Newspaper Puzzle)
- Puzzle | Elevator Puzzle
- Puzzle 27 | (Hourglasses Puzzle)
- Puzzle 29 | (Car Wheel Puzzle)
- Puzzle 31 | (Minimum cut Puzzle)
- Puzzle 33 | ( Rs 500 Note Puzzle )
- Puzzle 39 | (100 coins puzzle)

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.