Chapter CSB1.2, Problem 17E

To determine

To find: The GCF of the pair of numbers $20,21,25$ .

Answer to Problem 17E

  $\text{GCF}=1$

Explanation of Solution

Given information: The numbers $20,21,25$

The prime factors of the numbers are,

  $\begin{array}{l}20=2\cdot 2\cdot 5\\ 21=3\cdot 7\\ 25=5\cdot 5\end{array}$

  $\therefore \text{GCF}=1[\because \text{there is no common factor]}$

Thus, the GCF of the monomials $20,21,25$ is 1.