Digging trenches requires two types of labor: unskilled labor (aka workers) and skilled labor (aka supervisors). Unskilled labor can be hired for $50 per day, and skilled labor can be hired for $100 per day. If, by hiring another unskilled laborer, K&B Construction Company can dig another 20 feet of trenches per day, and if by hiring another skilled laborer, it can dig another 30 feet of trenches per day, is K&B Construction Company minimizing its costs?