NIMCET 2017 Question Paper with solutions

Given,
n(A) = 4 and n(B) = 2
∴ n(A x B) = n(A)-n(B)= 4x 2= 8
∴ Number of subsets of A x B = $2^{\mathit{n}\left(\mathit{A}\times \mathit{B}\right)}$
= $2^8$ = 256
∴ The number of subsets of the set Ax B, having atleast three elements is
= 256 - ($\stackrel{8}{}{\mathit{C}}_0+\stackrel{8}{}{\mathit{C}}_1+\stackrel{8}{}{\mathit{C}}_2)$
= 256 - (1 + 8 + 28) = 256 - 37 = 219