Answer: he doesn't need any more sugar since he already has two cups
Explanation:
According to his recipe, 1 cups of sugar is sufficient for 18 cupcakes; invariably, (18*2) = 36 cupcakes would require 2 cups of sugar.
1 cup = 18 cupcakes
X cups = 36 cupcakes
X = (36 * 1) / 2 = 2 cups of sugar.
And since he already has 2 cups of sugar, he doesn't need to get anymore sugar since he has what he needs.