Step 1 :The problem is asking for an inequality that represents the situation where the combined weight of children and adults exceeds the elevator's capacity.
Step 2 :The weight of the children is represented by 30x (since each child weighs 30 pounds) and the weight of the adults is represented by 120y (since each adult weighs 120 pounds).
Step 3 :The elevator's capacity is 3000 pounds.
Step 4 :Therefore, the inequality that represents the situation where the elevator is overloaded is \(30x + 120y > 3000\).
Step 5 :Final Answer: The inequality is \(\boxed{30x + 120y > 3000}\).