The task is to generate the correct answer for a given math problem.
--------
Question: Problem: a swimmer can swim in still water at 4 km / h . if the speed of the water current is 2 km / h , how many hours will the swimmer take to swim against the current for 5 km ?

Answer: 2.5


Question: Problem: a certain bacteria colony doubles in size every day for 25 days , at which point it reaches the limit of its habitat and can no longer grow . if two bacteria colonies start growing simultaneously , how many days will it take them to reach the habitat ’ s limit ?

Answer: 2


Question: Problem: 2,7 , 17,3 , 11,19 , 5,13 , __

Answer:
23