Question

While driving on the highway, Dave averages 60 miles per hour. In the city, he averages 30 miles per hour. On a trip to his grandmother's house, Dave drives 2 3/5 hours on the highway and 1 1/5 hours in the city.

Answer 1

I suppose you want to know the distance to grandmother's house....

(2 3/5)60+(1 1/5)30

(13/5)60+(6/5)30

780/5+180/5

960/5

192 miles

Answer 2

If you are asking for the total distance, it is 156 miles on the highway and 42 miles in the city, approximately 198 miles total