The task is to generate the correct answer for a given math problem.
--------
Question: Problem: a can do a piece of work in 22 days and b alone can do it in 10 days . b works at it for 5 days and then leaves . a alone can finish the remaining work in

Answer: 11 days


Question: Problem: in a university the average age in an arts class is 21 and average age in technical class is 18 . what is the age average of university if there are 8 arts classes and 5 technical classes ?

Answer: 19.85


Question: Problem: the average age of a family of 5 members is 20 years . if the age of the youngest member be 10 years then what was the average age of the family at the time of the birth of the youngest member ?

Answer:
12.5