Question 1135691
<pre>Start with both containers empty.

Fill the 3 liter container.

Pour it into the 5 liter container. 

(Now the 3 liter container is empty and the 5 liter container has 3 liters,
and has room for 2 more liters).

Fill the 3 liter container.

Use the full 3 liter container to just fill up the 5 liter container, which
takes away 2 liters from the 3 liters in the 3 liter container, leaving
exactly 1 liter in the 3 liter container. 

That's what you wanted!

Edwin</pre>