The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: a particular library has 75 books in a special collection , all of which were in the library at the beginning of the month . these book are occasionally loaned out through an inter - library program . if , by the end of the month , 80 percent of books that were loaned out are returned and there are 66 books in the special collection at that time , how many books of the special collection were loaned out during that month ?
[EX A]: 45

[EX Q]: Problem: a certain debt will be paid in 65 installments from january 1 to december 31 of a certain year . each of the first 20 payments is to be $ 410 ; each of the remaining payments is to be $ 65 more than each of the first 20 payments . what is the average ( arithmetic mean ) payment that will be made on the debt for the year ?
[EX A]: 455

[EX Q]: Problem: a man swims downstream 24 km and upstream 16 km taking 4 hours each time , what is the speed of the man in still water ?
[EX A]:
5