the question says binary equality
of 48 is 110000,
what is the relevance of this 48?
if you have a IT background then
this makes sense because 51-48 is
3 and binary equivalent of 3 is
11(one one not eleven).
so if you add 11 to 110000 it becomes
you really dont need a pen and paper
if you think this way. or else you can
go the traditional way if it confuses you.