Question

5.Which of the following cannot be a perfect square?
a.4.41
b.198
c.676
d. None of these

Answer 1

Answer:

b) 198.

Step-by-step explanation:

☆ The unit digit of a perfect square can only be 0, 1, 4, 5, 6 or 9.

Hope this will help you :)

Answer 2

Answer:

$\huge \mathfrak{ \fcolorbox{magenta}{magenta}{ \fcolorbox{aqua}{aqua}{ \color{blue}{✿ Question}}}}$

Which of the following cannot be a perfect square?

ⓐ4.41

ⓑ198

ⓒ676

ⓓ None of these

$\huge \mathfrak{ \fcolorbox{blue}{blue}{ \fcolorbox{aqua}{aqua}{ \color{magenta}{✿ Answer}}}}$

$\hugeⓑ198 \: { \pink{✓✓}}$

Reason :

Any number whose unit digit is 2,3,7 or 8 is not a perfect square.

Whereas those numbers whose unit digit is 0, 1, 4, 5, 6 or 9 is a perfect square.

$\large \frak{ \underline {\pink{Square \: root \: of} \: { \sf { \pink{4. 41}}}}}$

$= > \sqrt{4.41} = \sqrt{2.1^{2} }$

$= > \sqrt{4.41} = 2.1$

$2.1✓✓$

$\large \frak{ \underline {\purple{Square \: root \: of} \: { \sf { \purple{676}}}}}$

$= > \sqrt{676} = \sqrt{ {2}^{2} \times {13}^{2} }$

$= > \sqrt{676} = 2 \times 13 = 26$

$26✓✓$

$\sf{ \blue{Hope \: it \: helps}}$

$\huge{ \underline{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: }}$