# If A = |1, 2, 3, 4, 5|,

Question:

If A = |1, 2, 3, 4, 5|, then the number of proper subsets of A is

(a) 120

(b) 30

(c) 31

(d) 32

Solution:

(c) 31

The number of proper subsets of any set is given by the formula $2^{n}-1$, where $n$ is the number of elements in the set.

Here,

n = 5

$\therefore$ Number of proper subsets of $A=2^{5}-1=31$