Question

What is the GCF of 15, 35 and 95?

Answer 1

Hint: In this problem we need to calculate the GCF of the given numbers. We know that GCF means Greatest Common Factor. It can be calculated by observing the factors of the given numbers. So, we will first consider each given number separately and write the prime factorization form of the number. After writing prime factors of each number list the common factor for each given number. If we get only one common factor then that is our required GCF. If we get more than one common factor then the product of the common factors is the GCF of the given numbers.

Complete step-by-step solution:
Given numbers are $15$, $35$ and $95$.
Considering the number $15$. We can write the number $15$ by using its prime factors as
$15=3\times 5$
Considering the number $35$. We can write the number $35$ by using its prime factors as
$35=5\times 7$
Considering the number $95$. We can write the number $95$ by using its prime factors as
$95=5\times 19$
We can observe that the number $5$ is the only one common factor for all the given numbers which are $15$, $35$ and $95$.
Hence the Greatest Common Factor (GCF) of the given numbers $15$, $35$ and $95$ is $5$.

Note: In this problem they have only asked to calculate the GCF of the given numbers. Sometimes they may ask to calculate the Highest Common Factor (HCF) or Greatest Common Divisor (GCD). Then don't panic all the terms GCF, HCF, GCD are the same and follow the above procedure to calculate all of them.