#### Answer

16 students selected Tuesday as their first choice.

#### Work Step by Step

In the preference table, we can see that 9 students selected the days in the order T, W, F, M. We can see that 5 students selected the days in the order T, W, M, F. We can see that 2 students selected the days in the order T, M, W, F. All of these students selected Tuesday as their first choice.
Therefore, the number of students who selected Tuesday as their first choice is 9 + 5 + 2, which is 16.