Two finite sets have m and n elements respectively. the total no. of subset of the first

Two finite sets have m and n elements respectively. the total no. of subset of the first set is 56 more than the total no. of subsets of the second set. the values of m and n respectively will be

Let A and B be two sets having m and n numbers of elements respectively
number of subsets of A=2m
number of subsets of B=2n
according to question
2m-2n=56
2n(2m-n-1)=23(23-1)
therefore,
n=3 and m-n=3
m=6