Be sure to look for the solutions at the end of this blog article!
The Monty Hall Problem
Imagine being on a game show with three doors: one hides a prize, and the others hide nothing exciting. You pick a door, say No. 1, but before it’s opened, the host—who knows what’s behind the doors—opens another door, say No. 3, which reveals no prize. He then asks if you want to switch to door No. 2. What would you do? Are your chances better if you switch?
The Missing Dollar Riddle
Three friends share a $30 hotel room, paying $10 each. Later, they found out they were overcharged $5, so the hotel sent the bellhop back with the refund. Unable to divide the money evenly among the three, the bellhop gives each friend $1 and keeps $2 for himself. Each friend now paid $9, totaling $27. The bellhop has $2. But where’s the missing dollar?
Cheryl’s Birthday Puzzle
Cheryl tells her friends Albert and Bernard 10 possible birthday dates. She whispers the month to Albert and the day to Bernard. Based on what they know and say, can you figure out Cheryl’s exact birthday?
The Four 4s
How creative can you get with the number 4? Using exactly four 4s and any operations, try to create equations that result in numbers from 0 to 100. For instance, to get 16, you might write \(4 + 4 + 4 + 4\). What other numbers can you find?
The Farmer, Fox, Chicken, and Grain Puzzle
A farmer must get a fox, a chicken, and a grain sack across a river in a small boat that only holds one item besides himself. If he leaves the fox with the chicken, the chicken won’t last long, and the same goes for the chicken with the grain. What’s his strategy for getting everything across safely?
Solutions
Have you thought them over?
Let’s check your solutions:
- Monty Hall Problem: Switching doors is better because your chances of winning become 2/3.
- Missing Dollar Riddle: There’s no missing dollar. The $27 total includes the $25 room cost and the $2 the bellhop keeps. The math adds up perfectly.
- Cheryl’s Birthday Puzzle: This puzzle depends on the clues given about what Albert and Bernard know. Each setup might have a different answer, so check your clues.
- The Four 4s: There are many possible solutions here, and it’s a great exercise in creative thinking.
- Farmer, Fox, Chicken, and Grain Puzzle: Take the chicken across first. Return for the fox, taking the chicken back. Leave the chicken, take the grain across, then finally come back for the chicken.
We hope you enjoy these brain teasers.
It’s a great way to keep our minds sharp and have some fun along the way.
Happy puzzling, everyone.