Gregor forms two numbers with the digits 1,2,3,4,5 and 6. Both numbers have three digits, and each digit is used only once. Gregor adds these tow numbers. What is the greatest sum Gregor can obtain?
The first and second numbers could be 642 and 531; 641 and 532; 632 and 541; or 631 and 542... So that if you add each, they will have the same sum which is 1173.
