One week a librarian kept track of whether returned books were returned on time or not, and whether they had fewer than 200 pages or they had 200 pages or more. The results are shown in the table.

What is the probability that a randomly selected book returned that week was returned on time, given that it had 200 pages or more?




Returned on time

fewer than 200 pages—— 78

200 pages or more ——116



Returned late

Fewer than 200 pages ——-15
200 pages or more ——31