Five Brilliant Brain Teasers For The Week (04/08/25)

Another week, another batch of brainy goodness. These five teasers include two quick starters, two logic-driven puzzles, and one tricky finale to truly test your mental agility.

Scroll carefully — answers are at the end!

🧠 1. The Missing Day (Easy)

A man says:

“The day before yesterday, I was 25. Next year, I’ll be 28.”

How is this possible?

🧠 2. The Unreadable Word (Easy)

What common English word becomes shorter when you add two letters to it?

🧩 3. The Parking Spot (Medium)

You see the following numbers painted on parking spaces in a lot, arranged in this order:

16, 06, 68, 88, ?, 98

What number goes in the question mark?

🧩 4. The Three Switch Rooms (Medium)

You’re in a room with three switches, each connected to a light bulb in a separate room. You can flip the switches however you like, but can only enter the bulb rooms once.

All bulbs are off to start.

How do you figure out which switch controls which bulb?

🧠💥 5. The Poisoned Wine (Hard)

A king has 1,000 bottles of wine. One is poisoned. The poison is so deadly that even a single sip will kill — but it takes exactly 24 hours to take effect.

The king needs to identify the poisoned bottle within 24 hours.

He has 10 prisoners to test the wine on, and he doesn't mind losing a few.

What is the minimum number of prisoners required to find the poisoned bottle in just one day?

✅ Answers Below — How many did you crack?

1. The Missing Day

It’s possible if his birthday is December 31st.

Let’s say today is January 1st:

Two days ago (Dec 30), he was still 25

On Dec 31, he turned 26

This year he’ll turn 27

Next year, he’ll turn 28

✅

2. The Unreadable Word

The word is short.

Add “-er” and it becomes shorter.

✅

3. The Parking Spot

Flip the numbers upside-down:

You’ll see: 86, 87, 88, 89, 90, 91

So the missing number is 87.

✅

4. The Three Switch Rooms

Turn on Switch 1 for a few minutes, then turn it off.

Turn on Switch 2.

Leave Switch 3 off.

Go into the bulb rooms:

Bulb that’s on = Switch 2

Bulb that’s off but warm = Switch 1

Bulb that’s off and cold = Switch 3

✅

5. The Poisoned Wine

You can solve this using binary logic. Label the bottles 1–1000 in binary (up to 10 digits). Assign each of the 10 prisoners to represent one binary digit.

Each prisoner drinks from the bottles where their binary digit is “1”. After 24 hours, you read which combination of prisoners died — the pattern reveals the poisoned bottle's binary number.

So:

Answer: Only 10 prisoners are needed to test 1,000 bottles in a single round using binary encoding.

✅