a) Charles has 65 cookies and wants to share them with his 4 friends. He wants to give each friend the same number of cookies and make sure that he has given away as many as he can in that way. He will eat any that are left over.
Charles will give each friend cookies and eat himself.

b) There are 8 big fish in Lake Hiawatha. Each morning 148 small fish swim into the lake from the Hiawatha river.
For as long as there are enough small fish for each large fish to get at least one, the large fish eat one small fish per minute.
But when there are not enough left to go around, the large fish start fighting and the remaining small fish all escape.
This means that each large fish eats small fish and escape.

c) Max has a birdhouse with 7 feedholes through which a birdfeed pellet can be made to fall into a tray for a hungry bird.
In order for any bird to be fed there must be a bird at each feedhole and each bird must peck at a button above its feed hole
within 5 seconds of hearing a bell ring. If they do that, and there are at least 7 pellets in the food bin,
one pellet will fall from a central food bin into each feedhole. A group of 7 sparrows have learned how to use this feeding device.
When Max puts pellets in the food bin the bell rings once a minute and the birds eat until they cannot get any more food.
If Max puts 192 pellets into the food bin
each bird can eat pellets and pellets are left in the bin (because there are not enough left to provide one for each bird).