Teacher:In this task, you need to provide the correct option for a given problem from the provided options.
Teacher: Now, understand the problem? Solve this instance: Problem: in a certain animal shelter , the ratio of the number of dogs to the number of cats is 15 to 7 . if 20 additional cats were to be taken in by the shelter , the ratio of the number of dogs to the number of cats would be 15 to 11 . how many dogs are in the shelter ?
Options: a ) 75 , b ) 25 , c ) 30 , d ) 45 , e ) 60
Student:
a