Hello deathfromabove

Welcome to Math Help Forum!I'm assuming that the question means: what is the probability that we win at least one prize? In which case, we find the probability that we don't win any prizes, and subtract this from .

So, when the first ticket is drawn, there are losing tickets out of . The probability that one of these is chosen isIf we don't win on this draw, then there are then losing tickets out of the remaining. So the probability that one of these is chosen isSimilarly the probability that the third one chosen also loses isSo the probability that we don't win at all is:Therefore the probability that we win at least one prize isGrandad