Question

Find whether each of the following numbers is a perfect square or not.
a)121
b)55
c)81
d)49
e)69

Answer 1

Hi there !!


a) 121
Since the number has 1 in it's units place , it is a perfect square
Also, 11² = 121

b) 55
Since , the number has 5 in it's units place, it cannot be called a perfect square

c)81
Since the unit digit has 1 in it's units place, it is a perfect square
also,
9² = 81

d)49
Since the unit digit has 9 , it can be called as a perfect square
also,
7² = 49

e)69
The following number cannot be called as a perfect square since ✓69 = 8.3066....
because, the square roots of perfect squares cannot have decimal places.

Answer 2

Concept:

An integer that can be expressed as the square of another integer is called a perfect square.

Given:

We have five options having numbers: 121, 55, 81, 49, 69

Find:

We have to find a non-perfect square among five options: 121, 55, 81, 49, 69

Solution:

a) 121

Since the number 121 is a perfect square of 11

11² = 121

So, it is not the correct option.

b) 55

Since 55 is not the perfect square of any number, it cannot be called a perfect square.

So, it is the correct option.

c)81

Since the number 81 is a perfect square of 9

9² = 81

So, it is not the correct option.

d)49

Since the number 49 is a perfect square of 7

7² = 49

So, it is not the correct option.

e)69

Since 69 is not the perfect square of any number, it cannot be called a perfect square.

So, it is the correct option.

Hence, option "b" and "e"  is not perfect square.

#SPJ2