Question

What is the GCF of 90, 135, 225

Answer 1

Given

We are to find the Greatest Common Factor of 90, 135 and 225

First, we should decompose all numbers into their prime factors and write them as a product

`\begin{gathered} 90\text{ = 2 }*3\text{ }*\text{ 3 }*\text{ 5} \\ 135\text{ = }3\text{ }*\text{ 3 }*\text{ 3 }*\text{ 5} \\ 225\text{ = }3\text{ }*\text{ 3 }*\text{ }5\text{ }*\text{ 5} \end{gathered}`

Then we choose the common prime factors: 3, 3 and 5

The greatest common factor (GCF) is obtained by multiplying the common prime factors:

`\begin{gathered} \text{GCF = }3\text{ }*\text{ 3 }*\text{ 5} \\ =\text{ 45} \end{gathered}`

Hence, the GCF is 45.

Answer: 45