Question

Which of the following sets are finite?
$W=$ Set of days of the week
$S=$ Set of the solutions of the equation $x^2-16=0$
$G=$ Set of points on a line

• A. $W$ and $S$
• B. $W$ and $G$
• C. $S$ and $G$
• D. W,S and $G$

Answer 1

Answer: (A)

W contains finite number of elements as there are seven days in a week. So, it is finite.
The equation $x^2-16=0$ has two solutions. So, $S$ is finite.
There are infinite points on a line. So, $G$ is infinite.
Note All infinite sets cannot be described in the roster form.