Short Answer TypeIs 1372 a perfect cube? If not, find the smallest natural number by which 1372 must be multipled so that the product is a perfect cube.
We have 1372 = 2 x 2 x 7 x 7 x 7
Since, the prime factor 2 does not appear in a group of triples. 
∴ 1372 is not a perfect cube.
Obviously, to make it a perfect cube we need one more 2 as its factor.
i.e. [1372] x 2 = [2 x 2 x 7 x 7 x 7] x 2
or 2744 = 2 x 2 x 2 x 7 x 7 x 7
which is a perfect cube.
Thus, the required smallest number = 2.
Find the one’s digit of the cube of each of the following numbers.
(i) 3331 (ii) 8888 (iii) 149 (iv) 1005
(v) 1024 (vi) 77 (vii) 5022 (viii) 53
Consider the following pattern:
(a) 63 (b) 83 (c) 73
Long Answer TypeWhich of the following are perfect cubes?
1. 400 2. 3375 3. 8000 4. 15625
5. 9000 6. 6859 7. 2025 8. 10648
Check which of the following are perfect cubes.
(i) 2700 (ii) 16000 (iii) 64000 (iv) 900
(v) 125000 (vi) 36000 (vii) 21600 (viii) 10000
(ix) 27000000 (x) 1000
What pattern do you observe in these perfect cubes?
Short Answer TypeWhich of the following numbers are not perfect cubes? (i) 216 (ii) 128 (iii) 1000 (iv) 100 (v) 46656
Long Answer TypeFind the smallest number by which each of the following numbers must be multiplied to obtain a perfect cube. (i) 243 (ii) 256 (iii) 72 (iv) 675 (v) 100
Short Answer Type
Switch
