Puzzles Online
Puzzle 10 | (Know Average Salary without Disclosing Individual Salaries)
Three Employees want to know the average of their salaries. They are not allowed to share their individual salaries.
Answer:
1) X adds a Random Number and his salary and tells the sum to Y.
2) Y also adds a Random Number and his salary to the sum told by X and tells new sum to Z.
3) Z also adds a Random Number and his salary to the sum told by Y and tells new sum to X.
4) X subtracts its random number from the sum told by Z and tells the new number to Y.
5) Y subtracts its random number from the sum told by X and tells the new number to Z.
6) Z subtracts its random number from the sum told by Y and announces the new number.
The new number is now the sum of three salaries and average can be calculated by dividing the sum by 3.
Finally, nobody knows the salary of others, but all know average.
This can be extended to more than 3 employees also.