You’re sunbathing on the island shown on the map below. The island is six miles from shore at

Question

the closest point, and the nearest store is a convenience store seven miles down the beach. If
you can row at 4 miles an hour, and you can walk at 5 miles an hour, where should you land to
get a bag of tortilla chips in the least possible time? (Ignore tides, currents, and sharks. No fair
renting a helicopter.)

Answer 1

You should land at the closest point to the store, which is 6 miles away from the island.

If you row the 6 miles at 4 miles an hour, it will take you 6/4 = 1.5 hours to reach the shore.

Then, if you walk the 7 miles to the store at 5 miles an hour, it will take you 7/5 = 1.4 hours to reach the store.

Therefore, it will take you a total of 1.5 + 1.4 = 2.9 hours to get a bag of tortilla chips if you land at the point closest to the store.