Question

For A = {5,6,7} how many number of proper subsets will be formed?

• A. 7
• B. 8
• C. 9
• D. 6

Answer 1

The correct option is A

7

To calculate the number of possible proper subsets we use, $2^n$ - 1, where 'n' represents the number of a elements in the given set. So for A = {5,6,7}, we have, number of proper subsets as $2^3$ - 1 = 8 - 1 = 7. And the required subsets are,

{ }, {5}, {6}, {7}, {5,6}, {6,7} and {5,7}