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.

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