Question

find the number of subsets of A if A={x:x=4n+1,2<_n<_5,n€N}​

Answer 1

Answer:

A = .{x:x=4n+1}

A= {9,13,17,21}

No. of subset of A= 2n

=2A=16

n=4

Answer 2

Answer:

when, n=2 , x= 4(2)+1=9

n=3 , x= 13

n= 4 , x= 17

n= 5 , x= 21

A = {9,13,17,21} = n(A) =4 = n[P(A)] = 2 n(A)

= 2 power 4

= 16