Set up a proportion:
8/9/16 = 1/x
Cross multiply:
8/9x = 16
Divide 8/9 to both sides or multiply by its reciprocal, 9/8.
x = 16 * 9/8
x = 144/8
x = 18
So you have a total of 18 muffins, now subtract this from the amount that blew away to find out how many you have left.
18 - 16 = 2
So you have 2 muffins left.