Answer:
106 cupcakes for that Wednesday.
Explanation:
Let T stand for the total number of cupcakes the baker made on the Wednesday in question. We learn that 17% of the total were vanilla cupcakes, and that there were 18 of them. We can write that as:
(17%)*T = 18
(0.17)T = 18
T = 105.8
We'll round that up to 106 total cupcakes made on that Wednesday, including the 18 vanilla ones.