So many stats out there ..... what happens when we combine them ?

Last Start Winners win 15% of the time

The favourite wins 33% of the time

What is the probalitity that a favourite who won it's last start will win this time ?

This is not a trick question at all, I'm not like that ! I've tried to get my head around these things, read up on probability ..... and I'm more confused than ever.

Can any budding genius, or anyone with a pulse, give an opinion please.