Frank hiked up a mountain trail at at 6 am in the morning because at the very fresh for hiking on the mountain .. frank till evening time is when the sun already down, because if continue cannot be trail so Frank had walked up the mountain 12 hours long and then he take a rest.The next day frank down the mountain next to the same track. Frank the average speed is 12 miles per hour Because His average rate traveling uphill was kilometers per hour and his average rate downhill was kilometers per hour.

so frank total long was the trail is 24 kilometers