Question

The number of common prime factors of $75,60,105$ is

• A. $2$
• B. $3$
• C. $4$
• D. $5$

Answer 1

The correct option is A

$2$

Prime factor is a factor that is a prime number.

Prime factors of $75=3,5,5$

Prime factors of $60=2,2,3,5$

Prime factors of $105=3,5,7$

Common prime factors of $75,60,105$ are $3\mathrm{and}5$

thus the number of common prime factors of $75,60,105$ is $2$

Hence option (a) is correct option.