In this chapter, we provide RD Sharma Class 8 Solutions Chapter 4 Cubes and Cube Roots Ex 4.2 for English medium students, Which will very helpful for every student in their exams. Students can download the latest RD Sharma Class 8 Solutions Chapter 4 Cubes and Cube Roots Ex 4.2 Maths pdf, free RD Sharma Class 8 Solutions Chapter 4 Cubes and Cube Roots Ex 4.2 Maths book pdf download. Now you will get step by step solution to each question.

Textbook | NCERT |

Class | Class 8 |

Subject | Maths |

Chapter | Chapter 4 |

Chapter Name | Cubes and Cube Roots |

Exercise | Ex 4.2 |

**RD Sharma Solutions for Class 8 Chapter 4 Cubes and Cube Roots Ex 4.2** **Download PDF**

**Question 1.**

**Find the cubes of:**

**(i) -11**

**(ii) -12**

**(iii) – 21**

**Solution:**

(i) (-11)

^{3}=(-11)

^{3}=(11 x 11 x 11) =-1331

(ii) (-12)

^{3}=(-12)

^{3}=(12 x 12 x 12) = -1728

(iii) (-21)

^{3}=(-21)

^{3}=(21 x 21 x 21) = -9261

**Question 2.Which of the following numbers are cubes of negative integers.**

**(i) -64**

**(ii) -1056**

**(iii) -2197**

**(iv) -2744**

**(v) -42875**

**Solution:**

∴ All factors of 64 can be grouped in triplets of the equal factors completely.

∴ -64 is a perfect cube of negative integer.

All the factors of 1056 can be grouped in triplets of equal factors grouped completely

∴ 1058 is not a perfect cube of negative integer.

All the factors of -2197 can be grouped in triplets of equal factors completely

∴ 2197 is a perfect cube of negative integer,

All the factors of -2744 can be grouped in triplets of equal factors completely

∴ 2744 is a perfect cube of negative integer

All the factors of -42875 can be grouped in triplets of equal factors completely

∴ 42875 is a perfect cube of negative integer.

**Question 3.**

**Show that the following integers are cubes of negative integers. Also, find the integer whose cube is the given integer :**

**(i) -5832 (ii) -2744000**

**Solution:**

Grouping the factors in triplets of equal factors, we see that no factor is left

∴ -5832 is a perfect cube

Now taking one factor from each triplet we find that

-5832 is a cube of – (2 x 3 x 3) = -18

∴ Cube root of-5832 = -18

Grouping the factors in tuplets of equal factors, we see that no factor is left. Therefore it is a perfect cube.

Now taking one factor from each triplet, we find that.

-2744000 is a cube of – (2 x 2 x 5 x 7) ie. -140

∴ Cube root of -2744000 = -140

**Question 4.**

**Find the cube of :**

**Solution:**

**Question 5.Which of the following numbers are cubes of rational numbers :**

**Solution:**

**All Chapter RD Sharma Solutions For Class 8 Maths**

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**All Subject NCERT Solutions For Class 8**

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