The problem asks to write an expression for "triple the quantity $m$".

1. Problem Description

The problem asks to write an expression for "triple the quantity $m$".

2. Solution Steps

The word "triple" means to multiply by

3. The quantity is $m$.

Therefore, we need to multiply $m$ by

3. The expression is $3 \times m$, which can be written as $3m$.

3. Final Answer

$3m$