The goal is for one person to get all four boats to the other side in the least !
Question:
The goal is for one person to get all four boats to the other side in the least amount of time?
The only way to get from one side of the lake to the other is by driving the boats. Each boat can be driven across the lake individually or towing another boat. Towing more than one boat at a time is not allowed. If a boat is towed, the time to cross the lake is determined by the speed of the slowest boat. For example, if the red boat (2min) tows the green boat (7 min) it will take 7 mins to cross the lake. 4 boats are: Red 2 mins
Blue boat 3 mins
Green boat 7 mins
Yellow boat 10 mins
The answer is 21 minutes to cross. How did they do it?
Answers:
Foward: Blue (3) + Red (2) = 3
Back: Red (2) = 2
Foward: Green (7) + Yellow (10) = 10
Back: Blue (3) = 3
Foward: Blue (3) + Red (2) = 3
3+2+10+3+3=21 Min