Linear Inequalities

Concept:The total daily work output must be at least 30 units.Explanation:Let $x$ be the number of experienced persons and $y$ the number of fresh ones.Each experienced person does 5 units, so they contribute $5x$ units.Each fresh person does 3 units, so they contribute $3y$ units.The total output is $5x+3y$."At least 30" means the total must be greater than or equal to 30.Thus the inequality is $5x+3y \geq 30$.Answer:$5x+3y \geq 30$ matches option C.