Challenging your mind with math brain teasers and other types of puzzles keeps the connections between your brain cells sharp. Plus, learning how to solve brain teasers improves your ability to concentrate and focus, too! This big list of brain teasers for adults with answers will test your critical thinking skills–and even help you improve them—so you can learn how to solve brain teasers even faster thanks to all the practice you’re getting! So if you’re ready to put your mind to the test, dive in and see how many of these 101 brain teasers you can solve—without peeking at the answers!

101 Brain Teasers

  1. A doctor and a bus driver are both in love with the same woman, an attractive girl named Sarah. The bus driver had to go on a long bus trip that would last a week. Before he left, he gave Sarah seven apples. Why? An apple a day keeps the doctor away!
  2. I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What color was the bear? White, since the only place you can do that is the North Pole and polar bears are the only kind of bears that live there.
  3. A woman shoots her husband. Then she holds him underwater for over 5 minutes. Finally, she hangs him. But 5 minutes later they both go out together and enjoy a wonderful dinner together. How can this be? The woman was a photographer. She shot a picture of her husband, developed it, and hung it up to dry.
  4. What is special about these words: job, polish, herb? They are pronounced differently when the first letter is capitalized.
  5. I am taken from a mine, and shut up in a wooden case, from which I am never released, and yet I am used by almost everybody. What am I? Pencil lead
  6. A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it? The river was frozen
  7. I can’t be bought, but I can be stolen with a glance. I’m worthless to one, but priceless to two. What am I? Love
  8. Turn me on my side and I am everything. Cut me in half and I am nothing. What am I?  The number 8
  9. No matter how little or how much you use me, you change me every month. What am I? A calendar
  10. How can 8 + 8 = 4? When you think in terms of time. 8 AM + 8 hours= 4 o’clock.
  11. What has cities, but no houses; forests, but no trees; and water, but no fish? A map
  12. A red house is made from red bricks. A blue house is made from blue bricks. A yellow house is made from yellow bricks. What is a greenhouse made from?  Glass
  13. There is a word in the English language in which the first two letters signify a male, the first three letters signify a female, the first four signify a great man, and the whole word, a great woman. What is the word? Heroine
  14. In my hand I have two coins that are newly minted. Together, they total 30 cents. One isn’t a nickel. What are the coins?  A quarter and a nickel
  15. What is harder to catch the faster you run? Your breath
  16. You’re escaping a labyrinth and there are three exits. Exit A leads to an inferno. Exit B leads to an assassin. Exit C leads to a lion that hasn’t eaten in 3 years. Which exit do you pick?  Exit C. If a lion hasn’t eaten in 3 years, it has definitely starved to death.
  17. What fastens two people yet touches only one? A wedding ring
  18. What kind of running means walking? Running out of gas
  19. What can be swallowed, but can also swallow you? Pride
  20. They fill me up and you empty me, almost every day; if you raise my arm, I work the opposite way. What am I? A mailbox
  21. Which three letters can frighten a thief away? ICU
  22. First I am dried, then I am wet. The longer I swim, the more taste you get. What am I?  Tea
  23. Lovely and round, I shine with pale light, grown in the darkness, A lady’s delight. What am I? A pearl
  24. My voice is tender, my waist is slender and I’m often invited to play. Yet wherever I go I must take my bow or else I have nothing to say. What am I? A violin
  25. I am a box that holds keys without locks, yet they can unlock your soul. What am I? A piano
  26. I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone’s dirty business. What am I? A vacuum cleaner
  27. I have four wings, but cannot fly, I never laugh and never cry; On the same spot I’m always found, toiling away with little sound. What am I? A windmill
  28. What can be stolen, mistaken, or altered, yet never leaves you your entire life? Your identity
  29. Until I am measured, I am not known. Yet you miss me, when I have flown. What am I? Time
  30. Some try to hide, some try to cheat, but time will show, we always will meet. Try as you might, to guess my name, I promise you’ll know, when you do claim. Who am I? Death
  31. Four cars come to a four-way stop, all coming from a different direction. They can’t decide who got there first, so they all go forward at the same time. They do not crash into each other, but all four cars go. How is this possible? They all made right-hand turns
  32. Take one out and scratch my head, I am now black but once was red. What am I? A match
  33. I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back. None suffer to have me, but do from my lack. What am I? Sleep
  34. He has married many women, but has never been married. Who is he? A preacher
  35. My life is often a volume of grief, your help is needed to turn a new leaf. Stiff is my spine and my body is pale, but I’m always ready to tell a tale. What am I? A book
  36. What has no hands but might knock on your door, and if it does you better open up? Opportunity
  37. What do you throw out when you want to use it but take in when you don’t want to use it? An anchor
  38. I can be short and sometimes hot. When displayed, I rarely impress. What am I? Temper
  39. What can be driven although it doesn’t have wheels, sliced but stays whole? A golf ball
  40. The cost of making only the maker knows, Valueless if bought, but sometimes traded. A poor man may give one as easily as a king. When one is broken pain and deceit are assured. What is it? Promise
  41. What rocks but does not roll? A rocking chair
  42. Shoot at me a thousand times and I may still survive. But, one scratch from me and you will find your prospects take a dive. What am I? An eight-ball
  43. Why is the letter F like death? Because without it life is a lie, or it makes life a lie.
  44. You do not want to have it, But when you do have it, You do not want to lose it.  What is it? A lawsuit
  45. An elevator is on the ground floor. There are four people in the elevator including me. When the lift reaches the first floor, one person gets out and three people get in. The lift goes up to the second floor, 2 people get out, 6 people get in. It then goes up to the next floor up, no one gets out but 12 people get in. Halfway up to the next floor up the elevator cable snaps, it crashes to the floor. Everyone else dies in the elevator except me. How did I survive? I got off on the first floor
  46. Guess the next three letters in the series GTNTL. I, T, S. The complete sequence is the first letter of every word in the sentence.
  47. Arnold Schwarzenegger has a long one. Michael J. Fox has a short one. Madonna does not use hers. Bill Clinton always uses his. The Pope never uses his. What is it? Last name
  48. The number 8,549,176,320 is a unique number. What is so special about it? This is the only number that includes all the digits arranged in alphabetical order.
  49. Find a number less than 100 that is increased by one-fifth of its value when its digits are reversed. 45 (1/5 of 45 = 9, 9 + 45 = 54)
  50. What letter comes next in the following sequence? D R M F S L T_ D – each letter represents one note in the diatonic musical scale: Do, Re, Mi, Fa, Sol, La, Ti, Do
  51. You are in a place called Wally’s World and there is only one law. There is a mirror, but no reflection. There is pizza with cheese, but not sausage. There is pepper, but no salt. There is a door, yet no entrance or exit. What is the law? Each word in Wally’s World must contain double letters.
  52. I come in different shapes and sizes. Parts of me are curved, other parts are straight. You can put me anywhere you like, but there is only one right place for me. What am I? A puzzle piece
  53. I have no eyes, no legs, or ears, and I help move the earth. What am I? An earthworm
  54. A sundial has the fewest moving parts of any timepiece. Which has the most? An hourglass, with thousands of grains of sand
  55.  What is unusual about the following words: revive, banana, grammar, voodoo, assess, potato, dresser, uneven?  Take the first letter of each word and place it at the end. It will spell the same word backward.
  56. Put a coin into an empty bottle and insert a cork into the neck. How can you remove the coin without removing the cork or breaking the bottle? Push the cork down into the bottle. Then shake the coin out.
  57. In 1990, a person was 15 years old. In 1995, that same person was 10 years old. How can this be? The person was born in 2005 B.C.
  58. You’re standing in a hallway with three light switches on the wall, each of which turns on a different lamp inside a closed room. You can’t see inside the room, and you can’t open the door except to enter the room. You can enter the room only once, and when you do, all the lamps must be turned off. How can you tell which switch turns on which lamp? Turn on the right switch and leave it on for two minutes. After two minutes, turn on the middle switch and leave it on for one minute. When that minute is up, turn off both switches and enter the room. One light bulb will be hot (1st switch) and one will be warm (2nd switch). The cold bulb will correspond to the switch you didn’t turn on.
  59. Two boxers are in a match scheduled for 12 rounds. (Pure boxing only. There are no kicking or takedowns). One of the boxers gets knocked out after only six rounds, yet no man throws a punch. How is this possible? Both the boxers were female
  60. What does this mean? I RIGHT I Right between the eyes
  61. I have a large money box, 10 inches wide and 5 inches tall.  Roughly how many coins can I place until my money box is no longer empty? Just one, after which it will no longer be empty.
  62. Brothers and sisters I have none but this man’s father is my father’s son. Who is the man? The man is my son
  63. Who makes it, has no need of it. Who buys it, has no use for it. Who uses it can neither see nor feel it. What is it? A coffin
  64. What runs all around a backyard, yet never moves? A fence
  65. What tastes better than it smells? A tongue
  66. What has a bottom at the top? Legs
  67. What goes through cities and fields, but never moves? A road
  68. During which month do people sleep the least? February (there are usually fewer nights in February).
  69. What is made of water but if you put it into water it will die? An ice cube
  70. Which creature walks on four legs in the morning, two legs in the afternoon, and three legs in the evening? Man. He crawls on all fours as a baby, then walks on two feet as an adult, and then walks with a cane as an old man.
  71. What 4-letter word can be written forward, backward or upside down, and can still be read from left to right? Noon
  72. Take off my skin - I won’t cry, but you will! What am I? An onion
  73.  A family has two parents and six sons. Each of the sons has one sister. How many people are in the family?  Nine. Two parents, six sons, one daughter!
  74. The water level in a reservoir is low, but doubles every day. It takes 60 days to fill the reservoir. How long does it take for the reservoir to become half full? 59 days. If the water level doubles every day, the reservoir on any given day was half the size the day prior. If the reservoir is full on day 60, that means it was half full on day 59, not on day 30.
  75. How far can a squirrel run into the woods? Halfway. After that, he’s running back out of the woods.
  76. Which word logically comes next in this sequence? Spots, tops, pots, opts… Stop. All the words are anagrams of each other.
  77. Which tire doesn’t move when a car turns right? A spare tire
  78. What do an island and the letter “t” have in common? They are both in the middle of water
  79. Is the capital of Kentucky pronounced Louisville or Luee-ville? Neither. The capital is Frankfurt
  80. On which side of a chicken are there more feathers? The outside
  81. How can a man who shaves several times a day still sport a long beard? He’s a barber
  82. What coat goes on wet?  A coat of paint
  83. A rancher had 500 cows and took one shot that got them all. How did he do it? A panoramic photo
  84. What can’t talk but will reply when spoken to? An echo
  85. What can you keep after giving to someone? Your word
  86. A man dies of old age on his 25 birthday. How is this possible? He was born on February 29th
  87. I have branches, but no fruit, trunk or leaves. What am I? A bank
  88. The more of this there is, the less you see. What is it? Darkness
  89. Where does today come before yesterday? The dictionary
  90. What can’t be put in a saucepan? Its lid
  91. What is black when it’s clean and white when it’s dirty? A blackboard
  92. What can you hold in your left hand but not in your right? Your right elbow
  93. What has many keys but can’t open a single lock? A piano
  94. What is cut on a table, but is never eaten? A deck of cards
  95. What kind of band doesn’t play music? A rubber band
  96. What building has the most stories? The library
  97. It stalks the countryside with ears that can’t hear. What is it? Corn
  98. A man describes his daughters, saying, “They are all blonde, but two; all brunette but two; and all redheaded but two.” How many daughters does he have? Three. A blonde, a brunette and a redhead
  99. What is 3/7 chicken, 2/3 cat and 2/4 goat? Chicago
  100.  If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I? A mirror
  101. What would you find in the middle of Toronto? The letter “o” Keep the fun going by checking out this giant list of 250 “Would You Rather?” questions and 125 Trick Questions.

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