Question

Find the cube root of the following numbers by finding their ones and tens digit.
a) 4096
b) 8000
c) 12167
Find the cube root by prime factorisation
d) 15625​

Answer 1

Answer:

Step-by-step explanation:

A) 4096

The unit digit of 4096 is 6 so the unit digit of cube root 4096 would be 6

The no. 4 is between 1³ and 2²

The nearest ni. Is

1<4<8

1 ³ is near 4

Therefore , 16 is a cube of no. 4096

B) 8000

= the unit digit of cube no. 8000 is .............................0.

The no. 8 is between 1³and 2³

The no. 8 is near to 1<8<8

Hence 8 is near 2³

Therefore cube of no. will be 20.

C) 12167

The unit digit of cube root 12167 is 7 then the unit digit of cube no. will be 3

12 is between 2³ and 3³

11 is near to

8<12<27

Hence 8 is near to cube no. 2

Therefore the cube root of no. 12167 = 23

By prime factorization-

5÷15625

5÷3125

5÷625

5÷125

5÷25

5÷5

Therefore joining 5vs we get

5×5=25