Fastest Possible Map - worker question

[Rephren]

Hi, this is my first post on these forums as I have recently started to play on Battle.net and have only played about 200 games, and lost most of them, I only play on fastest possible map as for me it's the most fun, I don't intend to try become a win focussed player, I just want to have fun, but I do have a question, what number of workers is best to put on minerals? I usually put about 30-40 on minerals and 12 on gas (3 each ) is this about right?

Thanks and regards,
Rephren