In direct variation, we can express the relationship between two variables with a formula of the form \( y = kx \), where \( k \) is a constant.
In this case, let \( d \) represent the distance traveled in miles, and \( t \) represent the time in hours. The speed of the jet is given as 600 miles per hour (mph), which serves as our constant rate \( k \).
The direct variation equation can be formulated as:
\[ d = 600t \]
To find the distance travelled in three hours (\( t = 3 \)), we can substitute \( t \) into the equation:
\[ d = 600 \times 3 \] \[ d = 1800 \]
So, the jet travels 1800 miles in three hours.