A cinema has 100 seats.

Show how it is possible to sell exactly 100 tickets and take exactly £100 if the prices are

£10 for adults
50p for pensioners
10p for children

Is there only one solution?

Show that it is also possible to do when the prices change to:

£10 for adults
£ 1 for pensioners
50p for children

How many solutions are there this time?