Random Result Pool

Im trying to make a system where there are several scoreboard values of different numbers. For this example il say value one is 10, option 2 is 1, option 3 is 2. I need to make a system where their numbers are equal to the odds of their role being picked so option one would be 10 time more likely to happen than option 2 the reason i need them to be scoreboard values is so the chances of each result can be edited.
I explained it as well as I can think of but if you need a clarification let me know