I have a probability calculation for my work. There is a total user base of 125,

I have a probability calculation for my work. There is a total user base of 125,000,000 users. Company A has 15,000,000 users, company B has 4,000,000. Company A and B want to combine their data overlap and see the probability of finding that overlap with company C that has 20,000,000 users. The idea would be to create an excel where these user numbers can be adjusted for each company and the probability of matching C to the intersection of A and B is calculated.