More Puzzles

   Log inLog in 
 RegisterRegister Immediately 

Difficult Logic Problems
Three coworkers would like to know their average salary

Fri Dec 07, 2007 6:13 pm  by tartle

Three coworkers would like to know their average salary. how can they do it, without disclosing their own salaries?
Sat Mar 01, 2008 10:56 am  by aggynd

ask each coworker total of other two's salary. total the three figures and divide by two.
Sun Mar 30, 2008 12:42 pm  by Jeebok

Person A writes a number that is her salary plus a random amount (AS + AR) and hands it to B, without showing C. B then adds his salary plus a random amount (BS + BR) and passes to C (at each step, they write on a new paper and don't show the 3rd person). C adds CS + CR and passes to A. Now A subtracts her random number (AR), passes to B. B and C each subtract their random number and pass. After C is done, he shows the result and they divide by 3.

As has been noted already, there's no way to liar-proof the scheme.

It's also worth noting that once they know the average, any of the three knows the sum of the other 2 salaries.
Sat May 03, 2008 2:38 pm  by dedo

Jeebok, you got it!
Wed May 28, 2014 12:52 pm  by yuk

There's only need for the first person to add some number X, only known to him to his salary. Then B would get (X + A), C would get (X + A + B), and A would get (X+A+B+C), will subtract X and calculate the average.
Tue Jun 24, 2014 3:29 pm  by Satyajit Chakrabartty

Each one of the co-worker puts his salary in a box provided with a lock and only an opening small enough for currency notes to be put in. Each worker puts his salary in privacy. At the end, the amount in the box is totaled and divided by three to know the average salary.
Reply to topic
      All times are GMT
Page 1 of 1


Discussion Board Forum Index