Name a key which is hardest to turn.

You need to cut a round cake into eight equal pieces with just 3 cuts. Can you do it?

In the four images below, can you find the odd one out?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

What is the end of everything?

If a wheel has 54 spokes, how many spaces are there between the spokes?

In a classic wine shop, the list of three most popular wines are:
- The cost of 1 French wine bottle: 500$
- The cost of 1 German wine bottle: 100$
- The cost of 20 Dutch wine bottles: 100$

John entered the wine shop and he needs to buy
- All three types of wine bottles.
- Needs to buy Dutch wine bottles in multiples of 20.
- Need to buy 100 wine bottles in total.

John has only 10000$. How many wine bottles of each type, John must buy?

What can go up a chimney down, but can’t go down a chimney up?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?