Your friend Sam has been asked to prepare appetizers for auniversity reception. She has an unlimited amount of ingredients and 6 hours in which to prepare them. Sam can make 400 mini-sandwiches or 160 servings of melon slices topped with smoked salmon and a dab of sauceper hour.

• Sam's opportunity cost of making one mini-sandwich is_______
• Sam's opportunity cost of making one melon appetizer is ______
• Suppose the reception has been postponed, and Sam has an extra 4 hours to prepare. The opportunity cost of making one mini-sandwich is now __________________
• Suppose the reception has been postponed, and Sam has an extra 4 hours to prepare. The opportunity cost of making one melon appetizer is now ___________
• Suppose Sam's friend Chris helps by preparing the melon slices, increasing Sam's productivity to 400 mini-sandwiches or 400 melon appetizers per hour. The opportunity cost of making one mini-sandwich is now ___________
• Suppose Sam's friend Chris helps by preparing the melon slices, increasing Sam's productivity to 400 mini-sandwiches or 400 melon appetizers per hour. The opportunity cost of making one melon appetizer is now ____________