Short Question Answer: Cubes & Cubes Roots

Q1:
Ans:

Q2: Find the cubes of the following:
(a) 0.3
(b) 0.8
(c) (0.001)
(d) (2 - 0.3)

Ans:

(a) (0.3)³ = 0.3 × 0.3 × 0.3 = 0.027

(b) (0.8)³ = 0.8 × 0.8 × 0.8 = 0.512

(c) (0.001)³ = (0.001) × (0.001) × (0.001) = 0.000000001

(d) (2 - 0.3)³ = (1.7)³ = 1.7 × 1.7 × 1.7 = 4.913

Q3: Find the cube roots of
(i)
(ii) -0.729
Ans:

Q4:  135 a perfect cube?

Ans: Prime factorisation of 135, is:

135 = 3 × 3 × 3 × 5

We find that on making triplet, the number 5 does not make a group of the triplet.

Hence, 135 is not a perfect cube.

Q5:  Find the smallest number by which 1323 may be multiplied so that the product is a perfect cube.
Ans: Prime factorisation of 1323, is:
1323 = 3 × 3 × 3 × 7 × 7
Since we required one more 7 to make a triplet of 7.

Q6: Express the following numbers as the sum of odd numbers using the given pattern

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Q7: Observe the following pattern and complete the blank spaces.
1³ = 1

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