Answer: 13
Step-by-step explanation:
Mary has 16 3/4 cups of flour
She uses 1 1/3 cup and 2 5/12, we add the amount she uses together
1 1/3 + 2 5/12
4/3 + 29/12 = 16 + 29 / 12
=45/12 = 15/4
Amount left = amount has - amount used.
16 3/4 = 67 / 4
Amount left = 67 / 4 - 15 / 4
=52 / 4 =13