questions
The Bridge mRiddle
The Setup
Four people (A, B, C, and D) must cross a narrow bridge at night as fast as possible. How fast can the cross the bridge?
- Capacity: The bridge only holds two people at once.
- The Torch: The group has one flashlight. It is needed to cross the bridge.
- The Speeds: Each member in the group requires a different amount of time to cross the bridge. Person A requires 1 minute, B requires 2 minuntes, C requires 5 minutes, and D requires 10 minuntes.
- The Rule: A pair moves at the speed of the slower person.
The Solution
CLICK TO REVEAL
### Solution: 17 Minutes ## Step-by-Step Walkthrough: 1. **A & B** cross together — _2 minutes._ Total: **2 minutes** 2. **A** returns with the torch — _1 minute._ Total: **3 minutes** 3. **C & D** cross together — _10 minutes._ Total: **13 minutes** 4. **B** returns with the torch — _2 minutes._ Total: **15 minutes** 5. **A & B** cross together again — _2 minutes._ Total: **17 minutes!** **The Trick:** You must send the two slowest people (C & D) together so their times overlap, but neither of them should be the one to bring the torch back!
