Maxence brings 18 biscuits to class one day. On the same day, Thibaut brings 31 biscuits and Mehdi brings 23 biscuits. How many biscuits did they bring to class in all? (Answer in Roman numerals.)

The boundary of a stadium is to be repainted by a group of workers. If 5 workers can paint 473.5 m of the boundary in an hour, then how many meters of the boundary will 15 workers paint in an hour?

Three classes will go to the book fair in Vienna. The first class will arrive at the book fair at the time shown on the clock below:

Each class will spend 30 minutes at the book fair and then leave. The second class arrives at the book fair after the first class leave, and the third class will arrive after the second class leave. At what time will the third class leave the book fair?