# 10 Tough brain teasers that will totally stump your friends

If you hold to the belief that you either use it or lose it — whatever “it” is —you definitely don’t want to lose your mind.

Thankfully, neuroscience experts believe that human beings can stave off a decline in brain functioning by actively seeking out new experiences and puzzles throughout their lives. So whether you hope to exercise your brain cells or impress your friends with your intelligence, these 10 challenging brain teasers should suffice.

Give them a try! You can find the answers below.

### 1. Count to three

If you have three, you have three. If you have two, you have two. But if you have one, you have none. What is it?

### 2. What am I?

I can be quick and then I’m deadly. I am a rock, shell and bone medley. If I was made into a man, I’d make people dream. I gather in my millions by ocean, sea and stream. What am I?

### 3. A number game

When is 99 more than 100?

### 4. At the hotel

A man takes his car to a hotel. Once he reaches the hotel, he is declared bankrupt. Why?

### 5. Hint: It’s not your husband

If my name is spoken, I will be gone. Who or what am I?

Which word is shorter when you add two letters to it?

### 7. A doctor and a boy

A boy is walking down the road with a doctor. Although the boy is the doctor’s son, the doctor isn’t the boy’s father. Who is the doctor?

### 8. Hesitant inventor

The man who invented it doesn’t want it for himself. The man who buys it doesn’t buy it for himself. The man who needs it doesn’t know he needs it. What is it?

### 9. Aging, redefined

A writer was 50 years old in the year 2000 but 40 years old in the year 2010. How can this be possible?

Forwards it’s heavy, backwards it’s not.

Answers: 1) Choices, 2) Sand, 3) A microwave — if you set it for “99” it will run for 1 minute and 39 seconds, but if you set it for “100” it will run for 1 minute even, 4) The man is playing Monopoly, and lands on a property for which he cannot pay rent, 5) Silence, 6) Short, 7) The boy’s mother, 8) A coffin, 9) The writer lived in the era of B.C., not A.D., 10) Ton.
This post is brought to you by GSN, home of the brainteaser show Idiotest. Tune in to the premiere on April 1, and play along with their online game.