a) There are four jugs.
The largest holds exactly $9$ litres of drink, and is filled to the top.
The $7$ litre, $4$ litre and $2$ litre jugs are empty.
Find a way to pour the drink from one jug to another until you are left with exactly $3$ litres in three of the jugs.
b) You have three jugs one of which is full and holds $8$ litres.
The capacity of other jugs is not known. But, it is known that when using them every whole number quantity from $1$ litre to $8$ litres can be accurately measured out.
What could be the capacities of the $2$ other jugs?
How would you measure all the whole number quantities from $1$ to $8$ litres?