Question

If two different numbers are taken from the set $\{0,1,2,\mathrm{3............},10\}$; then the probability that their sum as well as absolute different are both multiple of $4$ , is :

Answer 1

The sample space here is equal to $55$.

Now the possible combinations are $\{0,4\},\{0,8\},\{2,6\},\{2,10\},\{4,8\},\{6,10\}$

so the answer is $6/55$.