Pat takes 4 hours to brew 5 L of beer and 2 hours to make a pizza. Kris takes 6 hours to brew 5 L of beer and 4 hours to make a pizza.

What is Pat and Kris's opportunity cost of making a pizza?

Think the problem through, then take a shot. The opportunity cost of making pizza is not making beer. Hint: how much beer would Pat NOT make if Pat made 2 pizzas?

Pat would not make 2.5 L of beer but i am confused about Kris.

Use the same math and procedure. For Pat, I believe you did the following calculations. To make 2 pizzas she would need 4 hours, which equals 5 L of beer -- So, one pizza would equal 2.5L of beer.

For Kris to make 1 pizza would take 4 hours or (4/6)*5 L of beer = 3.3333 L of beer. Ergo, Kris's opportunity cost for making pizza is higher than Pats. (Which will mean the Kris's opportunity cost for making beer is Lower than Pat's)

To calculate the opportunity cost of making a pizza for Kris, we can use the same approach we used for Pat.

Kris takes 6 hours to brew 5 L of beer. This means that in 1 hour, Kris can brew (5/6) L of beer. So, in 4 hours (the time it takes to make a pizza), Kris would brew (4 * (5/6)) L of beer, which is approximately 3.3333 L of beer.

Therefore, the opportunity cost of making a pizza for Kris is 3.3333 L of beer. This means that if Kris chooses to make a pizza, they would be sacrificing the production of 3.3333 L of beer.

Comparing it to Pat's opportunity cost, which is 2.5 L of beer for making a pizza, we can conclude that Kris's opportunity cost for making a pizza is higher than Pat's. This also implies that Kris's opportunity cost for making beer is lower than Pat's.