Calculate the median and mode of the following dataset: 15, 12, 23, 35, 46, 57, 18, 12, 39, 51, 32, 43, 25, 59, 18, 38, 45, 40, 32, 33

Here are the solutions to the questions based on the provided marks:
The marks obtained by students are:
15, 12, 23, 35, 46, 57, 18, 12, 39, 51, 32, 43, 25, 59, 18, 38, 45, 40, 32, 33

First, sort the data in ascending order:
12, 12, 15, 18, 18, 23, 25, 32, 32, 33, 35, 38, 39, 4