Statement 1: If B=U−A then n(B)=n(U)−n(A) where U is universal set.
Statement 2: For any three arbitrary sets A,B,C we have if C=A−B then n(C)=n(A)−n(B) .
Statement 1 is true, statement 2 is true; statement 2 is a correct explanation for statement 1.
statement I is true, statement 2 is true; statement 2 is not a correct explanation for statement 1.
Statement 1 is true, statement 2 is false
statement 1 is false, statement 2 is true.
If U is universal set then B=U−A=A′, for which n(B)=nA′=n(U)−n(A)
But for any three arbitrary sets A,B,C we cannot have always n(C)=n(A)−n(B) if C=A−B as it is not specified here that
weather A is universal set or not. In case A is not universal set we cannot conclude that n(C)=n(A)−n(B) .
Hence, statement 1 is true but statement 2 is false.