David charges $15 plus $5.50 per hour to mow lawns arie charges $12 plus $6.25 per hour to mow lawns. in what situation is aries charge greater than or equal to david’s charge?

Renee hiked for 6 3/4 miles. after resting, renee hiked back along the same route for 5 1/4 miles. how many more miles does renee need to hike to return to the place where she started? represent your answer as a simplified mixed number, if necessary.