This equation shows how the cost of a plumber's visit is related to its duration in hours.

Question

c = 20d

The variable d represents the duration of the visit in hours, and the variable c represents the cost. What is the duration, in hours, of a plumber's visit that costs $20?

Answer 1

To find the duration of a plumber's visit that costs $20, we can use the equation given:

\[ c = 20d \]

Here, \( c \) represents the cost, and \( d \) represents the duration in hours. We can substitute \( c = 20 \) into the equation:

\[ 20 = 20d \]

Next, we solve for \( d \) by dividing both sides by 20:

\[ d = \frac{20}{20} \]

\[ d = 1 \]

Therefore, the duration of the plumber's visit that costs $20 is 1 hour.