What happens if a Person spent money on good things which are earned from bad ways
There is no problem at all. It will have mixed result (if casue is really mixed) or each action will have it's own result (selling liquor - bad, generosity - good). Amount of the result is not just lineraly depend on the amount of action, it's also depend on the level of development of mind of the performer. There is more factors to play in the ripening of karma.