This is an utmost annoying question that i assume requires lots of patience(for people like me...)... or just a few secs for mathematicians...

Joe asked Penny to think of four different postive digits and add up the 24 different 4-digit numbers that could be made using the four digits. Then he asked her to subtract just one of the 4-digits numbers from the total and write down the new total. When asked what number she had written down, Penny replied: "122**0".

Joe didnt quite hear the 4th or 5th digits. But he was able to work out the number Penny had subtracted. What was that number?

well, is there any combinations of formluae that may work on this question? or can it be onli pure guess and check?

Thanx in advance