Question

The number of non-empty subsets of the set $\{1,2,3,4\}$ is $3\times a$. The value of ' $a$ ' is

• A. 3
• B. 4
• C. 5
• D. 6

Answer 1

Answer: (C)

Total number of subset of given set $\{1,2,3,4\}=2^4=16$
Since, $\varphi$ is the subset of every set.
$\therefore$ Number of non-empty subsets $=16-1=15=3\times 5$