Find:

(1) {a}

(2) {a,{a, b}}

(3) {a, b, c}

Solution :-

(1) {a} = {Φ, {a}}

(2) {a,{a,b}} = {Φ, {a}, {a,b}, {a,{a,b}}}

(3) {a,b,c} = {Φ, {a}, {b}, {c}, {a,b}, {b,c}, {a,c}, {a,b,c}}

Solution:

1) {a}

$ 2^n$ = $2^1$ = 2

p(s) = {$\varnothing$, {a}}

2) {a, {a, b}}

$ 2^n$ = $2^2$ = 4

p(s) = {$\varnothing$, {a}, {a, b}, {a, {a, b}} }

3) {a, b, c}

$ 2^n$ = $2^3$ = 8

p(s) = {$\varnothing$, {a}, {b}, {c}, {a, b}, {b, c}, {a, c}, {a, b, c} }