To determine the total cost of hiring firefighters, we need to account for both wages and benefits. Each firefighter has wages of $40,000 and benefits of $20,000, making their total cost $40,000 + $20,000 = $60,000.
If \( x \) represents the number of firefighters, the total cost for \( x \) firefighters would be \( 60,000x \).
Given that the total budget for the firefighters' wages and benefits is $600,000, we can write the equation as:
\[ 60,000x = 600,000 \]
Thus, the correct option from the responses provided is:
60,000x = 600,000