Our Earth has only one Moon, and that Moon is one Moon itself...I don't think Moons within Moons exsist.
Ganymede is itself a moon, and it has no stable moonlettes. So "zero" is your answer. Jupiter has 63 named bodies orbitting it, one of which is Ganymede.
Pluto has five moons - Charon, Nix, Hydra, S2011 & S2012
62 known Jupiter moons to be exact.
Venus has no moons.
Venus has no moons. It may have had some before but now it has no moons.
Venus has 0 moons.
Venus has no moons.
Venus has no moons.
Venus has no moons.
Venus does not have moons.
No. Neither Mercury nor Venus have any moons.
Venus has no moons.
No. Venus does not have any moons.
There are no moons revolving around Venus.