Question

Which of the following pairs of sets are not equal ?

• A. $A=\{1,5\},$ $B=\{2,4\}$
• B. $A=\{x:x+4=4\},$ $B=0$
• C. $A=\{2,4,6,8,10\},$ $B=\{x:x=2n,$ where $n\le 5$ and $n\in N\}$
• D. $A=1,\frac{1}{2},\frac{1}{3}$, $B=\frac{1}{n},n\in N$

Answer 1

The correct option is A $A=\{1,5\},$ $B=\{2,4\}$

Two sets are equal only when they have exactly the same elements.
From the given options we see that $A=1,5,B=2,4$ are not equal as they have different elements