NIMCET 2017 — Mathematics PYQ

Concept:
The number of elements in the power set of any set $A$ is $2^n$ where $n$ is the number of elements of the set $A$.

Calculation:

Given, set $S=2,1,4$

Number of elements in set $S=2$

$\therefore$ The number of elements in the power set $P(S)=2^2=4$

Hence, option (2) is correct.