RBSE Solutions for Class 8 Maths Chapter 2 Cube and Cube Roots Ex 2.1

RBSE Solutions for Class 8 Maths Chapter 2 Cube and Cube Roots Ex 2.1 is part of RBSE Solutions for Class 8 Maths. Here we have given Rajasthan Board RBSE Class 8 Maths Chapter 2 Cube and Cube Roots In Text Exercise 2.1.

Board	RBSE
Textbook	SIERT, Rajasthan
Class	Class 8
Subject	Maths
Chapter	Chapter 2
Chapter Name	Cube and Cube Roots
Exercise	Exercise 2.1
Number of Questions	4
Category	RBSE Solutions

Rajasthan Board RBSE Class 8 Maths Chapter 2 Cube and Cube Roots Ex 2.1

Question 1.
Which of the following numbers(RBSESolutions.com)are not perfect cube?
(i) 512
(ii) 243
(iii) 1000
(iv) 100
(v) 2700
Solution
(i) 512
Resolving 512 into Prime factors as follows

Here, all factors are in(RBSESolutions.com)groups of three.
Therefore. 512 is a perfect cube.

(ii) 243
Resolving 243 into Prime factors as follows

Here, 3 is not in groups of three. Therefore,
243 is not a(RBSESolutions.com)perfect cube.

(iii) 1000
Resolving 1000 into prime factors as follows

Here, factors 2 and 5 are in groups of three.
Therefore, 1000 is(RBSESolutions.com)not a perfect cube.

(iv) 100
Resolving 100 into Prime factors as follows

Here, factors 2 and 5 are not in groups of three. Therefore, 100 is not a perfect cube.

(v) 2700
Resolving 2700 into Prime factors as follows

Here, factors 2 and 5 are not a groups of three. Therefore, 2700 is not a perfect cube.

Question 2.
Find out the smallest number multiplied by the following numbers to get the perfect cube?
(i) 108
(ii) 500
(iii) 5400
(iv) 10584
Solution
(i) 108
Resolving 108 into Prime factors(RBSESolutions.com)as follows

Here, factor 2 is not in groups of three.
∴ to make 108 as a perfect cube, we have to multiply it by smallest number 2.

(ii) 500
Resolving 500 into Prime factors as follows

Here, factor 2 is not in group of three
∴ to make 500 a perfect cube, we have to multiply it by smallest number 2

(iii) 5400
Resolving 5400 into Prime factors as follows

Here, factor 5 is not ¡n group of three.
∴ to make 5400 a perfect(RBSESolutions.com)cube, we have to multiply it by smallest number 5

(iv) 10584
Resolving 10584 into Prime factors as follows

Here , factor 7 is not in group of three
∴ to make 10584 as a perfect cube, we have to multiply it by smallest number 7.

Question 3.
Find out the smallest number by which following numbers must be divided to get the perfect cube.
(i) 24
(ii) 250
(iii) 192
(iv) 135
Solution.
(i) 24
Resolving 24 into Prime factors as follows

Here, factor 3 is not in group of three so 24 is not a perfect cube.
Therefore, the smallest number(RBSESolutions.com)by which us should be divided to make it a perfect cube is 3.

(ii) 250
Resolving 250 into Prime factors as follows

Here, factor 2 is not in group of three.
∴ The smallest number by which 250 should be divided to make it a perfect cube is 2.

(iii) 192
Resolving 192 into Prime factors as follows
Here , factor 3 is not in group of three.
∴ The smallest number by which 192 should be divided to make it perfect cube is 3.

(iv) 135
Resolving 135 into Prime factors as follows

Here. factor 5 is not in group of three
∴ the smallest number(RBSESolutions.com)by which 135, should be divided to make it perfect cube is 5.

Question 4.
Rehan works in soap factor. He is playing with arranging cubic soap by making cubes. If he has to arrange 216 soap then how many soaps will occur in first line of cube.
Solution
Total Soap = 216
Resolving 216 into Prime factors as follows

Number of soaps in first row of cube = 6 soaps.

We hope the given RBSE Solutions for Class 8 Maths Chapter 2 Cube and Cube Roots Ex 2.1 will help you. If you have any query regarding Rajasthan Board RBSE Class 8 Maths Chapter 2 Cube and Cube Roots In Text Exercise 2.1, drop a comment below and we will get back to you at the earliest.