In a study examining the survival of cancer, patients, 100 patients were

In a study examining the survival of cancer, patients, 100 patients were

Subject: Mathematics    / Statistics
Question

In a study examining the survival of cancer patients, 100 patients were enrolled at baseline. After one year, 20 patients were known to have died. Assuming no patients were lost to follow-up, what was the probability of surviving one year? (OK to show numerator/denominator)