# Ch – 7 Cubes & Cube Roots

Q.1: The cube of 4 is _________.

a) 16

b) 64

c) 12

Q.2: Which of the following is the smallest Hardy-Ramanujan number ?

a) 1774

b) 1724

c) 1729

Q.3: The smallest number by which 135 must be divided, in order to get a perfect cube is ____________.

a) 4

b) 3

c) 5

Q.4: Numbers obtained when a number is multiplied by itself three times is known as ________ numbers.

a) cube

b) square

c) none  https://amzn.to/3mWqkto

Q.5: Is 243 a perfect cube ?

a) Yes

b) No

c) Can’t say

Q.6: Which is the smallest three-digit perfect cube number ?

a) 125

b) 100

c) 343

Q.7: What will be the unit digit of a number having ‘3’ at its ones place ?

a) 9

b) 7

c) 3

Q.8: 729 is the cube of _____.

a) 8

b) 6

c) 9

Q.9: Which of the following is true for any natural number ?

a) square of ‘a’ is greater than cube of ‘a’

b) square of ‘a’ is lesser than cube of ‘a’

c) square of ‘a’ is equal to cube of ‘a’  https://amzn.to/3o0zV3F

Q.10: What is the volume of a cube whose edge is 5 cm ?

a) 125

b) 250

c) 300

Q.11: How many zeroes will be there in the cube of 40 ?

a) two

b) three

c) four

Q.12: Which of the following smallest number has to be multiplied with 675 in order to get a perfect cube ?

a) 3

b) 7

c) 5

Q.13: The cube root of 0.027 is _________

a) 0.3

b) 0.03

c) 0.003

Q.14: The one’s digit of the cube of 888 is _________.

a) 2

b) 8

c) 6  https://amzn.to/2JugkKg

Q.15: Each prime factor appears ________ times in its cubes.

a) two

b) three

c) four

Q.16: The smallest number which has to be multiplied with 392 in order to get a perfect cube is __________.

a) 2

b) 5

c) 7

Q.17: The cube of even numbers is always _________.

a) even

b) odd

c) both

Q.18: The cube of 11 is __________.

a) 1331

b) 1221

c) 1111

Q.19: Figures which have three-dimensions are called _______ figures.

a) perfect

b) solid

c) regular  https://amzn.to/38MkfLb

Q.20: Check whether 27000000 is a perfect cube or not ?

a) Yes, it is a perfect cube

b) No, it is not a perfect cube

c) Can’t say  https://amzn.to/2MfOZwp

1. b
2. c
3. c
4. a
5. b
6. a
7. b
8. c
9. b
10. a
11. b
12. c
13. a
14. a
15. b
16. c
17. a
18. a
19. b
20. a  https://amzn.to/2Jsccuj