Flaw in proposed salaries puzzle solution With reference to the solution proposed by scott cooper on techinterview.org. At the end of the process, B knows. BS : His own salary BR : The random number he used AS + AR : A's salary + A's randum number AS + BS + BR + CS + CR : The total after A's subtracted his random number. (AS+BS+CS)/3 : The average salary Now he can deduce as follows: (AS+BS+CS)/3*3 = AS+BS+CS AS + BS + BR + CS + CR - AS+BS+CS = BR + CR BR + CR - BR = CR Which he can then use to determine the rest of the unknowns. Here is an alternative solution. Agree on a physical representation of an amount, say one match represents 10K, A, B and C all dump there matches into a bag, the contents is counted and divided by three. Kees Snijders Monday, April 14, 2003 I have to respectfully disagree.  Determining CR doesn't help B to determine anything else.  All he/she has now is: BS, BR, (AS + AR), (AS + CS). Let's say that AS + AR = a and AS + CS = b.  How you can derive values of 3 unknowns from just 2 equations? Mark Gershaft Wednesday, May 07, 2003 B also knows AS+BS+CS+BR+CR. Which can give AS+CS+CR, from which he can get CR. Once he get CR, he can get AR, AS, and CS. nagasatish Friday, May 16, 2003 How does he get AR after getting CR ? indian programmer Thursday, June 19, 2003   Fog Creek Home