Think about it this way The girl is doing one can so 16 ounces plus 3 cans of water so 16 times 3 + 16 more. so you could just do 16 times 4 which is 64 and depending on how you are answering it you could say she needs a pitcher that can hold 64oz or you could say she needs a pitcher that holds 8cups I hope that helps ^-^. and it would be 8 cups because 8oz equals a cup.