How to swap two variables, without using third variable ?

Ans is :  a=a+b; b=a-b; a=a-b;  Any other solution? a=a*b/(b=a); b=(a+b)-(a=b); use xor to swap  a = a^b b= a^b a= a^b Ans is :  a=a*b; b=a/b; a=a/b;