RS Aggarwal solution class 8 chapter 3 Squares and Square roots Exercise 3H

Exercise 3H

Q1 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 1:

Tick (✓) the correct answer
Which of the following numbers is not a perfect square?
(a) 7056
(b) 3969
(c) 5478
(d) 4624

Answer 1:

(c) 5478

According to the properties of squares, a number ending in 2, 3, 7 or 8 is not a perfect square.

Q2 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 2:

Tick (✓) the correct answer
Which of the following numbers is not a perfect square?
(a) 1444
(b) 3136
(c) 961
(d) 2222

Answer 2:

(d) 2222

According to the property of squares, a number ending in 2, 3, 7 or 8 is not a perfect square.

Q3 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 3:

Tick (✓) the correct answer
Which of the following numbers is not a perfect square?
(a) 1843
(b) 3721
(c) 1024
(d) 1296

Answer 3:

(a) 1843
According to the property of squares, a number ending in 2, 3, 7 and 8 is not a perfect square.

Q4 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 4:

Tick (✓) the correct answer
Which of the following numbers is not a perfect square?
(a) 1156
(b) 4787
(c) 2704
(d) 3969

Answer 4:

(b) 4787

By the property of squares, a number ending in 2, 3,7 or 8 is not a perfect square.

Q5 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 5:

Tick (✓) the correct answer
Which of the following numbers is not a perfect square?
(a) 3600
(b) 6400
(c) 81000
(d) 2500

Answer 5:

(c) 81000

According to the property of squares, a number ending in odd number of zeroes is not a perfect square.

Q6 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 6:

Tick (✓) the correct answer
Which of the following cannot be the unit digit of a perfect square number?
(a) 6
(b) 1
(c) 9
(d) 8

Answer 6:

(d) 8

According to the property of squares, a perfect square cannot have 2, 3, 7 or 8 as the unit digit.

Q7 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 7:

Tick (✓) the correct answer
The square of a proper fraction is
(a) larger than the fraction
(b) smaller than the fraction
(c) equal to the fraction
(d) none of these

Answer 7:

(b) smaller than the fraction

Q8 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 8:

Tick (✓) the correct answer
If n is odd, then (1 + 3 + 5 + 7 +... to n terms) is equal to
(a) (n² + 1)
(b) (n² − 1)
(c) n²
(d) (2n² + 1)

Answer 8:

(c) $n^2$

Q9 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 9:

Tick (✓) the correct answer
Which of the following is a Pythagorean triplet?
(a) (2, 3, 5)
(b) (5, 7, 9)
(c) (6, 9, 11)
(d) (8, 15, 17)

Answer 9:

(d) (8,15,17)

This can be understood from the property of Pythagorean triplets. According to this property, for a natural number m, $(2m, m^2-1, m^2+1)$ is a Pythagorean triplet.
Here,  m = 4
          2m = 8
          m² - 1=15
and    m² + 1 = 17

Q10 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 10:

Tick (✓) the correct answer
What least number must be subtracted from 176 to make it a perfect square?
(a) 16
(b) 10
(c) 7
(d) 4

Answer 10:

(c) 7

$$\begin{gathered} (176-7)=169 \\ \sqrt{169}=13 \end{gathered}$$

Q11 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 11:

Tick (✓) the correct answer
What least number must be added to 526 to make it a perfect square?
(a) 3
(b) 2
(c) 1
(d) 6

Answer 11:

(a) 3

$$\begin{gathered} 526+3=529 \\ 529={23}^2 \end{gathered}$$

Page-59

Q12 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 12:

Tick (✓) the correct answer
What least number must be added to 15370 to make it a perfect square?
(a) 4
(b) 6
(c) 8
(d) 9

Answer 12:

(b) 6

$$\begin{gathered} 15370+6=15376 \\ \sqrt{15376}=124 \end{gathered}$$

Q13 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 13:

Tick (✓) the correct answer
$\sqrt{0.9}=?$
(a) 0.3
(b) 0.03
(c) 0.33
(d) 0.94

Answer 13:

(d) 0.94



$\sqrt{0.9}=0.94$

Q14 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 14:

Tick (✓) the correct answer
$\sqrt{0.1}=?$
(a) 0.1
(b) 0.01
(c) 0.316
(d) none of these

Answer 14:

(c) 0.316

Using long division method:



∴ $\sqrt{0.1}= 0.316$

Q15 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 15:

Tick (✓) the correct answer
$\sqrt{0.9}\times \sqrt{1.6}=?$
(a) 0.12
(b) 1.2
(c) 0.75
(d) 12

Answer 15:

(b) 1.2

 $\sqrt{0.9}\times \sqrt{1.6}=\sqrt{1.44}=1.2$

Q16 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 16:

Tick (✓) the correct answer
$\frac{\sqrt{288}}{\sqrt{128}}=?$
(a) $\frac{\sqrt{3}}{2}$
(b) $\frac{3}{\sqrt{2}}$
(c) $\frac{3}{2}$
(d) 1.49

Answer 16:

(c) $\frac{3}{2}$

 $\frac{\sqrt{288}}{\sqrt{128}}=\sqrt{\frac{288}{128}}=\sqrt{\frac{2\times 2\times 2\times 2\times 2\times 3\times 3}{2\times 2\times 2\times 2\times 2\times 2\times 2}}=\sqrt{\frac{3\times 3}{2\times 2}}=\frac{\sqrt{3\times 3}}{\sqrt{2\times 2}}=\frac{3}{2}$

Q17 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 17:

Tick (✓) the correct answer
$\sqrt{2\frac{1}{4}}=?$
(a) $2\frac{1}{2}$
(b) $1\frac{1}{2}$
(c) $1\frac{1}{4}$
(d) none of these

Answer 17:

(b) $1\frac{1}{2}$

 $\sqrt{2\frac{1}{4}}=\sqrt{\frac{9}{4}}=\frac{\sqrt{9}}{\sqrt{4}}=\frac{3}{2}=1\frac{1}{2}$

Q18 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 18:

Tick (✓) the correct answer
Which of the following is the square of an even number?
(a) 196
(b) 441
(c) 625
(d) 529

Answer 18:

(a) 196

Square of an even number is always an even number.

Q19 | Ex-3H | Class 8 | RS AGGARWAL | Squares and Square roots | Chapter 3 | myhelper

OPEN IN YOUTUBE

Question 19:

Tick (✓) the correct answer
Which of the following is the square of an odd number?
(a) 2116
(b) 3844
(c) 1369
(d) 2500

Answer 19:

(c) 1369

Square of an odd number is always an odd number.