Question

The Gotemba walking trail up Mount Fuji is about 9 kilometres (km) long. Walkers need to return from the 18 km walk by 8 pm. Toshi estimates that he can walk up the mountain at 1.5 kilometres per hour on average, and down at twice that speed. These speeds take into account meal breaks and rest times. Using Toshi's estimated speeds, what is the latest time he can begin his walk so that he can return by 8 pm?

Answer 1

Answer:

He must start his journey by 11 AM

Step-by-step explanation:

Speed of Toshi while walking up the mountains is 1.5 kilometres per hour

Speed of Toshi while walking down  the mountains = 2 * Speed of Toshi while walking up the mountains = 3 kilometres per hour

Time taken to travel 9 Km in the upward direction by Toshi = 9 Km/1.5 kilometres per hour = 6 hours

Time taken to travel 9 Km in the downward direction by Toshi = 9 Km/3 kilometres per hour = 3 hours

He will take total 6 hours + 3 hours = 9 hours to travel 18 Km distance

Thus, He must start his journey by 11 AM