On condition that 1g = 100c and the person paid 9c, you should pay 91c. Therefore, you should fork out 9s1c, on condition that 10s = 100c, which means that 1s = 10c. I’m not sure how that can assist you with all your math, I just do it in https://chancekcqep.isblog.net/everything-about-beta78-40268988