Teacher:The task is to generate the correct answer for a given math problem.
Teacher: Now, understand the problem? Solve this instance: Problem: yesterday it took robert 3 hours to drive from city a to city b . today it took robert 2.5 hours to drive back from city to city a along the same route . if he had saved 30 minutes in both trips , the speed for the round trip would be 80 miles per hour . what is the distance between city a and city b ?
Student:
180