Question

Which of the following are perfect squares?
A. $25,36,49$
B. $64,19,72$
C. $18,30,42$
D. $45,32,42$

Answer 1

Hint: In this question, we have to find the perfect square. We know the perfect squares are the numbers that are the products of the number itself. These numbers are non-negative. For example we have $9$ , which is a perfect square. We can express this number as $3 \times 3$ . Now by applying this we can identify the perfect squares from the given numbers.

Complete step-by-step answer:
Here we have to find the perfect squares.
Let us take the first option where we have
$25,36,49$ .
We will now check the product of these numbers whether they can be expressed as the product of the number itself or not.
So we can write $25$ as $5 \times 5 = {5^2}$ .
So we can say that $25$ is a perfect square.
Again we have $36$
So we can write $36$ as
 $6 \times 6 = {6^2}$ .
So we can say that $36$ is a perfect square.
Similarly we will calculate for $49$ .
This can be expressed $49$ as
$7 \times 7 = {7^2}$ .
So we can say that $49$ is a perfect square.
We can see that all the numbers from this option are perfect squares.
And the rest of the numbers are not perfect squares.
Hence the correct option is (a) $25,36,49$

So, the correct answer is “Option A”.

Note: We should note that all the other numbers in the given options are non-perfect squares or prime numbers. A prime number is nothing but a number that has only two factors i.e. $1$ and itself. Such as we have $19$ , it is an example of a prime number from the given option. We should know that a non-perfect square is a number that there is no rational number i.e. it is considered as an irrational number.