if it is no specific mapping(onto or whatever)
then the answer is simply
n!/nn
1) A mapping is selcted at ranodm frm d set of all d mappings of d set A={1,2,3.....n} into itself .d probabbility that d mapping selcted is one to one is ?
no of one-one mappings n!
no of mappings = nn or (n+1)n or what.. i leave this to u!
if it is no specific mapping(onto or whatever)
then the answer is simply
n!/nn
yeah silly me really d options wer ulta fulta evn though they gave d same results so gt confused
neways thank u