If A= 2,3,5 and U be the set of prime factors of 210 then find A’.

The correct answer is Option (3) → $\{7\}$

$210=2*3*5*7 ⇒ U = \{2,3,5,7\}$.

Complement of a set A is a set which contains elements of U which are not the elements of A.

So, $A’=U-A=\{2,3,5,7\} – \{2,3,5\} = \{7\}$.