5
Tyre advice
(feddit.uk)
Yes.
As long as they're 559s they're gonna fit. You could also go narrower (42-559) or wider (55-559) and it would still fit the same rim because they are all the same, correct diameter of 559 mm.
If you go extremely wide or narrow you might maybe need a wider or narrower rim, but 47-559 and 50-559 are practically identical.
I thought that might be the case, but best to check with someone who knows better just in case. Cheers for the reply :)