BRAIN TRIVIA
Logic Puzzle: Four people need to cross a bridge in 17 minutes. They all walk at different speeds:
Person A: can cross the bridge in 1 minute
Person B: 2 minutes
Person C: 5 minutes
Person D: 10 minutes
Only two people can cross at the same time, and they must carry a flashlight. Someone has to bring the flashlight back each time.
How can all four cross in exactly 17 minutes?
Hint:
It might be tempting to have the Person A shuttle everyone, but that would take 19 minutes. Who do you pair with the slowest person?
Solution:
A and B cross (2 minutes)
A returns (1 minute)
C and D cross (10 minutes)
B returns (2 minutes)
A and B cross (2 minutes)
Total: 17 minutes!