Jugs

You have two jugs with a given capacity. The object is to obtain a specified number of pints in either of the jugs. The following operations are permitted:

You can fill either of the jugs.

You can empty either jug.

You can transfer the contents from one jug to the other, as much fluid as possible is transfered, the excess, if any, remains in the source jug.

There are three problems, they should be attempted in order.

Puzzle one. The first puzzle involves jugs of capacity 7 and 10. The object is to obtain 9 pints.
Puzzle two.
Puzzle three.

References

A quick look at this type of problem.
"Measuring with Jugs" Paolo Boldi, Massimo Santini and Sebastiano Vigna.