During the first two hours of a 4-h trip, the force of the wind causes a sailboat to travel 68 km. During the next two hours, the wind speed changes. The boat sails 3 km in the next hour and 25 km in the last hour. What was the boat's AVERAGE speed?

24 km/hr

Step-by-step explanation:

Speed is the rate of distance traveled in a defined time. Average speed is to take calculate the total distance travel at different speeds dividing by the total time taken.

Total Time = 4 hours

Total Distance = 68 km + 3 km + 25 km = 96 km

Average Speed = Total Distance / Total Time taken= 96 km / 4 hours

Average Speed = 24 km per hour

this is answer of 144 cubic meters