Missing information

For each problem, work out which is the missing piece of information.

At the beginning of the school year, the teacher gives two books to each pupil. How many books has she given?

 the start of the new school year
the teacher's name
the number of pupils
Sophie took the 8 :15 a.m. train from Lille to Paris. What time did she get to Paris? the length of the journey
the speed of the train
the distance Lille-Paris
You have to climb 84 steps to get to the first floor of the Eiffel Tower. How many steps are there between the first and the last floor? the height of the Eiffel Tower
the total number of floors
the total number of steps