Answer: There are 15 routes from Ruth Ann's school to her home with a stop at the library
Step-by-step explanation:
Since we have given that
Number of routes she can choose Ruth Ann from to get from school to the library = 3
Number of routes she can choose Ruth Ann from to get from the library to her home = 5
Number of routes from Ruth Ann's school to her home with a stop at the library is given by

Hence, there are 15 routes from Ruth Ann's school to her home with a stop at the library.