What least number can be multiplied by 165375 to make it a perfect cube?
- A2
- B5
- C7
- D49
Solution & Step-by-step Explanation
To find the least number that should be multiplied by 165375 to make it a perfect cube, we first find the prime factorization of 165375.
Let's divide 165375 by its prime factors:
165375÷5=33075
33075÷5=6615
6615÷5=1323
1323÷3=441
441÷3=147
147÷3=49
49÷7=7
7÷7=1
So, the prime factorization of 165375 is:
165375=3
3
×5
3
×7
2
For a number to be a perfect cube, the power of each prime factor in its prime factorization must be a multiple of 3.
The power of 3 is 3 (already a perfect cube).
The power of 5 is 3 (already a perfect cube).
The power of 7 is 2. To make it a perfect cube, it needs to be multiplied by 7
1
.
Therefore, the least number to be multiplied is 7.
Let's divide 165375 by its prime factors:
165375÷5=33075
33075÷5=6615
6615÷5=1323
1323÷3=441
441÷3=147
147÷3=49
49÷7=7
7÷7=1
So, the prime factorization of 165375 is:
165375=3
3
×5
3
×7
2
For a number to be a perfect cube, the power of each prime factor in its prime factorization must be a multiple of 3.
The power of 3 is 3 (already a perfect cube).
The power of 5 is 3 (already a perfect cube).
The power of 7 is 2. To make it a perfect cube, it needs to be multiplied by 7
1
.
Therefore, the least number to be multiplied is 7.