## Grade 8 Maths Cubes and Cube Roots Multiple Choice Questions (MCQs)

1. **Which of the following is not a perfect cube?**

(a) 1

(b) 9

(c) 8

(d) 27

2. **The value of 5 ^{3} is ………………. .**

(a) 125

(b) 15

(c) 10

(d) 75

3. **The cube of an even number is always ………………… .**

(a) odd number

(b) even number

(c) prime number

(d) none of these

4. **The cube of an odd number is always ………………… .**

(a) odd number

(b) even number

(c) prime number

(d) none of these

5. **Each prime factor appears ………………. times in its cube?**

(a) 2

(b) 3

(c) 1

(d) 4

6. **Which of the following is Hardy-Ramanujan Number?**

(a) 1724

(b) 1725

(c) 1727

(d) 1729

7. **The smallest natural number by which 704 must be divided to obtain a perfect cube is**

(a) 22

(b) 12

(c) 11

(d) 13

8. **The expansion of a ^{3} is …………………. .**

(a) 3 × a

(b) a + a + a

(c) 3 × 3 × 3

(d) a × a × a

9. **A cuboid has dimensions 5 cm, 2 cm, 5 cm. How many such cuboid will be needed to form a cube?**

(a) 20

(b) 10

(c) 5

(d) 2

10. **How many cuboids of dimensions 15 cm, 30 cm, 15 cm will be needed to form a cube?**

(a) 15

(b) 4

(c) 30

(d) 5

11. **The symbol for cube root is ……………… .**

(a)

(b)

(c)

(d) None of these

12. **The value of is ……………….. .**

(a) 8

(b) 7

(c) 6

(d) 3

13. **If the volume of a cube is 125 cm ^{3} then what would be the length of its side?**

(a) 25

(b) 5

(c) 4

(d) 15

14.** 9 is the cube root of ………………….. .**

(a) 343

(b) 729

(c) 629

(d) 81

15. **How many digits will be there in the cube root of 46656?**

(a) 2

(b) 1

(c) 3

(d) 4

16. **How many digits will I be there in the cube root of 512?**

(a) 1

(b) 2

(c) 3

(d) 4

17. **What will be the unit digit of ?**

(a) 5

(b) 0

(c) 3

(d) 4

18. **How many zeros will be there in the cube root of 27000?**

(a) 3

(b) 0

(c) 1

(d) 2

19. **If 8 ^{3} = 512, then = ………………… .**

(a) 3

(b) 7

(c) 13

(d) 8

20. **Find the cube root of 0.0027.**

(a) 3

(b) 0.3

(c) 0.03

(d) None of these

### Class 8 Maths Cubes and Cube Roots Fill In The Blanks

1. There are ……………… perfect cubes between 1 and 1000.

2. Cube of a number ending 7 will end in the digit ……………… .

3. A perfect cube can be expressed as the product of ……………….. prime factors.

4. Sum of the cubes of first 3 natural numbers is equal to ………………. of their sum.

5. The least number by which 72 be multiplied to make it a perfect cube is ……………….. .

### Class 8 Maths Cubes and Cube Roots True(T) Or False(F)

1. There are five perfect cubes between 1 and 100.

2. For an integer a, a^{3} is always greater than a^{2}.

3. Let x and y be natural number. If x divides y, then x^{3} divides y^{3}.

4.

5. Cube roots of 1 are +1 and -1.

### Class 8 Maths Cubes and Cube Roots Very Short Answer Type Questions

1. Which is the smallest three-digit perfect cube?

2. Which is the greatest three-digit perfect cube?

3. By which smallest natural number 392 must be multiplied so as to make the product a perfect cube?

4. What will be the unit digit of the cube of a number ending with 2?

5. What will be the unit digit of the cube root of a number ends with 8?

6. What will be the unit digit of ?

### Class 8 Maths Cubes and Cube Roots Short Answer Type Questions

1. If a^{3} – 1 = 1330, then a = ………………….

2. Find the cube root of .

3. If then =

4. Three numbers are in the ratio 1:2:3 and the sum of their cubes is 288. Find the numbers.

### Class 8 Maths Cubes and Cube Roots Long Answer Type Questions

1. Find the cube root of 13824 by prime factorisation method.

2. Parikshit makes a cuboid of plasticine of side 5 cm, 2 cm, 5 cm. Flow many such cuboids will be need to form a cube?

3. What will be the ten’s digit of the cube root of 91125?