To find the ratio of the number of students who want lemonade to the number of students who want iced tea, you can express it as:
\[ \text{Ratio} = \frac{\text{Number of students who want lemonade}}{\text{Number of students who want iced tea}} = \frac{32}{15} \]
This can be simplified, but in this case, 32 and 15 have no common factors other than 1, so the ratio remains 32:15.
Thus, the answer is 32:15.