In a small town, there are 100 residents, 70 of whom are homeowners, and 30 are renters. Among the homeowners, 50 own single-family homes, while the remaining 20 own condos. Among the renters, 10 are renting single-family homes and 20 are renting condos. A family is selected at random from the town. What is the probability that the family is either a homeowner or renting a single-family home?