Given the following reasoning and answer, what was the question? Bobbie has 18 * 3 = 54 crayons. Lizzie has 54 / 2 = 27 crayons.
 The answer: 27
The question Lizzie has half as many crayons as Bobbie. Bobbie has three times as many crayons as Billie. If Billie has 18 crayons, how many crayons does Lizzie have?