what is the probability of a urn having a ball? what is the probability of exactly r urns having at least one bowl in each urn of size how many urns in the urn how many urns hold balls randomly average probability of a urn containing at least one ball how many urns hold the most ball what is the probability of exactly three urns containing at least one ball? what is the probability of exactly three urns in different sizes? how many urns have at least 3 balls how many urns will hold a ball of the same size what is the probability of at least three urns containing at least one ball what is probability of exactly three urns having at least one ball which urns have seven balls? what is the probability for the first urn having at least one ball what is the probability of exactly three urns of at least one ball? how many urns can hold at least one ball which two urns have at least one ball how to figure the probability of at least one urn having seven balls of size? what is the probability of exactly three urns containing at least one ball? how to find the probability of having more than one urn