How many subsets in all are there of a set containing 4 elements?

How many subsets in all are there of a set with cardinal number 6?

How many proper subsets in all are there of a set with cardinal number 5?

Which of the following statements are true ?

(i) {a} ⊂ {a, b, c}

(ii) {a} ⊂ {b, c, d, e}

(iii) Φ ⊂ {a, b, c}

(iv) Φ ∈ {a, b, c}

(v) 0 ∉ Φ

(vi) {1} ⊂ {0, 1}

(vii) Every subset of a finite set is finite.

(viii) Every subset of an infinite set is infinite.