Given that Ben sold 30 tons of fruit and was able to sell greater than or equal to three times as much fruit as Zachary, we can let \( f \) represent the tons of fruit Zachary sold. The relationship can be modeled by the inequality:
\[ 30 \geq 3f \]
This inequality states that Ben's sales (30 tons) are greater than or equal to three times the amount of fruit Zachary sold.