Q.
Assertion (A) The power set of the set {1,2} is the set {ϕ,{1},{2},{1,2}}.
Reason (R) The power set is set of all subsets of the set.
Solution:
The subsets of the sets {1,2} are ϕ,{1},{2} and {1,2}.
So, P(A)={ϕ,{1},{2},{1,2}}
∴A is true. Also, R is true and R is the correct explanation of A.