We are building a light garden shed base (there will not be anything heavy
in there) and we were advised to buy two bags of cement to mix with six bags
of sand and six bags of ballast. Then advised to mix it on a board with the
ratio of one shovel of cement: to one bag of sand plus one bag of ballast.

But we have now decided that we should hire one of these small electric
mixers, which in the hire company catalogue says the mixer will hold up to
85 litres of cement.

What would be the best way to load up such a mixer please? Would it hold
one complete bag of sand plus one bag of ballast or would that be too much
weight for it? Also how much cement and water would I add?

Just to confuse us even more, we have just seen in the Wickes good idea
leaflet that they recomment a ratio of 1:3:6 (cement,sand,ballast) for shed
bases.

Basically we just want the simplest and easiest way to measure out
ingredients; plus how much water to use such a small mixer. Grateful for
advice.