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Cube and cube roots
Choose the correct option:
1.
2.
Find the cube of 75.
a.
421875
c.
400175
5625
417675
Find the prime factorisation of 175616.
23 × 23 × 33 × 7 3
2 3 × 23 × 2 3 × 7 3
a.
b.
c.
3.
b.
d.
23 × 33 × 53 × 7 3
d.
What is the cube of double of ‘a’?
a.
2a
b.
c.
8a3
d.
23 × 33 × 33 × 7 3
4a2
16a3
4.
Find the ones digit of cube root of 2197.
a.
7
b.
5
c.
9
d.
3
5.
Find the cubes of 2x, 3x and 4x.
a.
8x3, 16x3, 64x3
b.
2
2
2
c.
8x , 27x , 64x
d.
4x3, 9x3, 16x3
4x2, 9x2, 16x2
Fill in the blanks:
6.
The numbers 1, 8, 27... are _______________________________________.
7.
A natural number is said to be a perfect cube, if it is the cube of some ___________________________________.
8.
If ‘a’ is a non-zero number, then a × a × a = a3 is called ______________________________
of ‘ a ’
.
9.
36x is a perfect cube number, then x = ______________________________________
10.
Express 63 as the sum of odd numbers.
11. Is 53240 a perfect cube? If not, then by which smallest natural number should 53240 be divided so that the quotient
is a perfect cube?
12.
Is 68600 a perfect cube? If not, find the smallest number by which 68600 must be multiplied to get a perfect cube.
Answers
1.
a
2.
b
3.
c
4.
d
5.
a
6.
cube numbers
7.
natural number
8.
cube
9.
6
10.
31 + 33 + 35 + 37 + 39 + 41
11.
No, 5
12.
No, 5