For more than three years weve been puting small change into a container and several pushkas for tzedaka, some of it was given al daas that it would go to my old yeshiva because since I never paid full tuition I figured it was the least I could do, also some was earmarked(again all this mentally) for the beis hamussar near mir, and yet others was for a brother in law of mine, last but not least a good amount wasnt earmarkerd at all. Now that we moved houses the money got mixed all together and we have no way of knowing how much goes to each, What should we do with the mixture?
Interesting question. The best thing to do in this situation would be first of all to try and approximate, how much of the sum was inside each of the pushkas. After that, when you bring the money to each of the designated places, mention to them that their money got mixed up with other tzedakahs, and that this sum is only an approximation of what you gave. Then ask them if they are mochel if there is indeed a discrepancy. This way, since the tzedakah or the gabbai of the tzedakah is mochel it for a different tzedakah it is fine. Additionally, since you have the other money that wasn’t earmarked at all, if you will add some of that money to the money of each of the three, might very possibly have given each one the amount or more then what was already in each pushka.
B’orach tzedakah 16- 46, Poskim