Q51Written answer
The product of two perfect squares is a perfect square.
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Worked solution
Solution:-
True.
Let us take two perfect square 4 and 9.
Then, product of two perfect square is = 4 × 9 = 36
NCERT Exemplar · Class 8 · Maths
Chapter 3: Squares and Square Roots & Cubes and Cube Roots
Practice each question, then open the answer or worked solution.
Questions
142 questionsQ52Written answer
There is no square number between 50 and 60.
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Worked solution
Solution:-
True.
Q53Written answer
The square root of 1521 is 31.
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Solution:-
False.
The square root of 1521 is 39.
Q54Written answer
Each prime factor appears 3 times in its cube.
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Solution:-
True.
We know that, a perfect cube can always be expressed as the product of triplets of prime factors.
Q55Written answer
The square of 2.8 is 78.4.
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Worked solution
Solution:-
False.
= 2.82
= (28/10)2
= 784/100
= 7.84
Q56Written answer
The cube of 0.4 is 0.064.
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Worked solution
Solution:-
True.
= 0.43
= (4/10)3
= 64/1000
= 0.064
Q57Written answer
The square root of 0.9 is 0.3.
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Worked solution
Solution:-
False.
= √0.9
= 0.9487
0.9 = 0.32
= 0.3 × 0.3
= 0.09
Q58Written answer
The square of every natural number is always greater than the number itself.
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Worked solution
Solution:-
False.
As 1 is a natural number and the square of 1 is not greater itself rather its equal to the number itself
Thus, the given statement is not always true.
Q59Written answer
The cube root of 8000 is 200.
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Solution:-
False
3√8000 = 20
Q60Written answer
There are five perfect cubes between 1 and 100.
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Worked solution
Solution:-
False.
There are only 3 perfect cubes between 1 and 100.
2 × 2 × 2 = 8
3 × 3 × 3 = 27
4 × 4 × 4 = 64