Talk:Spring 2015 Event/@comment-84.90.161.45-20150510171234/@comment-26082284-20150510210257

''also probabilities don't work like that, if you could just multiply, you'd end up with ridiculous things like 50% chance = 100% chance in 2 sortie. ''

Eh? Isn't it obvious from that number that I wasn't simply multiplying? Actually, calculation goes like that: if we accept that 1.3% is the chance of getting Roma (as opposed to no drops and other kanmusu drops), then chance of NOT GETTING her  is 98.7%. And chances of NOT GETTING Roma within 100 sorties is 98.7% to the power of 100, which equals to about 27%. So, since there are only two possible outcomes: you'll get her or not, then chance of GETTING her within 100 or less sorties is 100-27=73%.