What Psychodad described was the Reserve requirement, which was indeed 10% in the US, but higher or lower in other Countrys. The Reserve requirement has been abolished last year and has been replaced by what the Feds call ample-reserves system.
But even before that suretys (Yes suretys, because if you "loan" more money than you got, it isn't a loan at all) were much higher than that, because banks could sell off those obligations, which could in turn be bought with suretys by the bank. Making the amount essentially limitless.
I bet you wish your bank in Avonmora was able to do that.