Find the missing factor.

$90=5\times$ 

Find the HCF of 3, 7 and 15. 

(A) 7 

(B) 15 

(C) 3 

(D) 1 

Make a factor tree for $14$. Do not use $1$ as a factor.

Using prime factorization method, find the HCF of the following numbers:

$144, 180$ and $192$

Find the common factors of $25$ and $40$.

Make a factor tree for $50$. Do not use $1$ as a factor.

Find the common factors of $28$ and $42$.

Highest common factor of two numbers is greater than each of the two numbers.

Make a factor tree for $48$. Do not use $1$ as a factor.

Find the factors of $60$.