If Tina swins 4 miles upstream at 1mph and back downstream to the same point at 4 mphwhat is her average speed?

To find Tina's average speed for the entire trip, we first calculate the total distance and total time. She swims 4 miles upstream at 1 mph, taking 4 hours, and then swims 4 miles downstream at 4 mph, taking 1 hour. The total distance is 8 miles, and the total time is 5 hours. Her average speed is therefore total distance divided by total time, which is 8 miles / 5 hours = 1.6 mph.