The numbers 0-9 are lined up in a row, like this:
0 1 2 3 4 5 6 7 8 9
You have to put in + and - signs in the blanks, so that in the end it will all equal 1.
Also, if possible, try to make expressions resulting in 0 and -1.
(In reply to re: Solution plus
In answer to your question, Chris, I say there is nothing "illegal" about combining two or more digits (e.g. 12). The problem says to put + and - signs in the blanks, but it does not say one has to put them in all the blanks, so why limit myself?
Now then, if we consider the possibility that multiple digits may be combined in the equation, obviously one can achieve numbers greater than 45. The question becomes: what is the first positive integer that cannot be achieved?
Posted by Bryan
on 2003-05-21 09:16:50