Explanation

To find out how many persons are required to arrange 725 books in 5 hours, let's first determine the rate at which the persons arrange books.

11 persons arranged 319 books in 4 hours.

Rate = 319 books / (11 persons * 4 hours) = 319 / 44 = 7.25 books per person per hour.

Now, let's calculate how many persons are needed to arrange 725 books in 5 hours at the same rate:

Total work = 725 books

Time = 5 hours

Rate per person = 7.25 books per hour

Persons required = Total work / (Rate per person * Time)

= 725 / (7.25 * 5)

= 725 / 36.25

= 20