We study the recently introduced random walk problems of partial covering t
ime (PCT) and random covering time (RCT). We generalize the concept of firs
t-passage time to a given set of m sites by considering the probability of
visiting all m sites for the first time on the tth step. For the one-dimens
ional case we derive an explicit result for the mean time needed to visit m
sites for the first time. Using this result we are able to solve the PCT a
nd RCT problems exactly in one dimension.