Answer:
The number of gallons must be greater than or equal to 6,500
Explanation:
Let
x -----> the number of gallons of paint need to sell
we know that
The number of gallons multiplied by $10 minus the cost of the new graffiti must be greater than or equal to $50,000
so
The inequality that represent this situation is

Solve for x
Adds 15,000 both sides


Divide by 10 both sides

The number of gallons must be greater than or equal to 6,500