Kids Riddles

Free printable

Printable riddle sheet — Ages 18+

32 riddles, ready to print — with the answer key on its own page.

This sheet is made to print. Use your browser's Print option (Ctrl/Cmd + P) or save it as a PDF — the answer key prints on its own page so it's easy to keep separate.

Ages 18+ — The Deep End riddle sheet

32 riddles across 4 categories · write your guess on the line, then check the answer key at the end.

Wordplay

  1. 1. Start with the word STARTLING. Remove exactly one letter at a time, and after every single removal, what remains must still be a real English word — all the way down to one letter. What's the sequence?

    My guess: ______________________________________________

  2. 2. What five-letter palindrome (reads the same forwards and backwards) names a small boat you paddle?

    My guess: ______________________________________________

  3. 3. Rearrange the letters of the word LISTEN to form another common word — one that describes paying quiet attention.

    My guess: ______________________________________________

  4. 4. What single word describes both a financial institution and the sloped land beside a river?

    My guess: ______________________________________________

  5. 5. What seven-letter word — spelled T-H-E-R-E-I-N — contains, without skipping or rearranging any letters, all of these five smaller words hidden inside it: 'the,' 'he,' 'her,' 'here,' and 'rein'?

    My guess: ______________________________________________

  6. 6. What word famously means the exact same thing whether or not you add the prefix 'in-' to the front of it — to the eternal confusion of firefighters?

    My guess: ______________________________________________

  7. 7. What is the only number from one to a hundred whose letters, spelled out in English, appear in strict alphabetical order?

    My guess: ______________________________________________

  8. 8. What is the longest common English word that can be typed using only the left hand on a standard QWERTY keyboard?

    My guess: ______________________________________________

Math & Logic

  1. 9. Three switches outside a windowless room each control one of three light bulbs inside. You can flip the switches as many times as you like, but you may only enter the room once. How do you determine, with total certainty, which switch controls which bulb?

    My guess: ______________________________________________

  2. 10. You have two identical eggs and a 100-floor building. You want to find the highest floor an egg can be dropped from without breaking, using as few worst-case drops as possible. What's the optimal worst-case number of drops?

    My guess: ______________________________________________

  3. 11. A man must cross a river carrying a wolf, a goat, and a bag of cabbage, one at a time in a small boat. Left alone, the wolf eats the goat, and the goat eats the cabbage. How does he get everything across safely?

    My guess: ______________________________________________

  4. 12. What comes next in this sequence, and why: 1, 11, 21, 1211, 111221, ?

    My guess: ______________________________________________

  5. 13. You have 12 identical-looking coins, and exactly one is counterfeit — either heavier or lighter than the rest, but you don't know which. Using a balance scale, what's the minimum number of weighings needed to both identify the counterfeit coin and determine whether it's heavier or lighter?

    My guess: ______________________________________________

  6. 14. Four people need to cross a rickety bridge at night, sharing one flashlight that must be carried on every crossing. The bridge holds only two people at a time, and a pair moves at the slower person's pace. Crossing times are 1, 2, 5, and 10 minutes. What is the minimum total time for everyone to cross?

    My guess: ______________________________________________

  7. 15. If it takes 5 people 5 hours to paint 5 identical fences, how long does it take 10 people to paint 10 identical fences, at the same steady rate?

    My guess: ______________________________________________

  8. 16. A father is currently 4 times as old as his son. In 20 years, he'll be exactly twice as old as his son. How old are they now?

    My guess: ______________________________________________

Lateral Thinking

  1. 17. A man is found dead in an open field, holding an unopened package. There are no other footprints anywhere nearby, and he clearly died from a fall — but there's no cliff, building, or ledge anywhere around. How did he die?

    My guess: ______________________________________________

  2. 18. A woman gives birth to two sons, born in the same hour of the same day of the same year, to the same two biological parents — yet they are not twins. How is that possible?

    My guess: ______________________________________________

  3. 19. You're on a game show facing three closed doors: a car behind one, goats behind the other two. You pick door #1. The host, who knows what's behind every door, opens door #3 to reveal a goat, then offers you the choice to switch to door #2 or stay with door #1. To maximize your odds of winning the car, what should you do, and what are your odds?

    My guess: ______________________________________________

  4. 20. A woman living in a small town has legally married ten different men from that same town. None of them died, none of them divorced her, and she broke no law. How is that possible?

    My guess: ______________________________________________

  5. 21. A man is walking the wrong way down a one-way street, and passes at least ten police officers along the way. None of them stop him or say a word. Why not?

    My guess: ______________________________________________

  6. 22. A man drinks a glass of punch at a party and leaves early. Later that night, everyone else who drank the punch becomes seriously ill. He's completely fine. Why didn't he get sick too?

    My guess: ______________________________________________

  7. 23. A woman claims she can predict the exact final score of any football (soccer) match before it even kicks off, every single time, without fail. How is this possible?

    My guess: ______________________________________________

  8. 24. What can go up a chimney down, but cannot go down a chimney up?

    My guess: ______________________________________________

Trivia

  1. 25. In which century did Johannes Gutenberg's printing press revolutionize the spread of the written word in Europe?

    My guess: ______________________________________________

  2. 26. What is the only mammal capable of true, sustained flight?

    My guess: ______________________________________________

  3. 27. Which element has the chemical symbol 'Fe'?

    My guess: ______________________________________________

  4. 28. What is the collective noun for a group of crows?

    My guess: ______________________________________________

  5. 29. Who painted the ceiling of the Sistine Chapel?

    My guess: ______________________________________________

  6. 30. What is the smallest prime number?

    My guess: ______________________________________________

  7. 31. What economic term describes a situation where prices keep rising while economic growth stalls and unemployment stays high?

    My guess: ______________________________________________

  8. 32. Besides echidnas, what is the only other living mammal that lays eggs?

    My guess: ______________________________________________

Answer key — Ages 18+

Wordplay

  1. 1. STARTLING → STARTING → STARING → STRING → STING → SING → SIN → IN → I — Each step removes one letter (L, then T, then A, then R, then T, then G, then S, then N) and every intermediate result is a valid word.
  2. 2. Kayak
  3. 3. Silent — LISTEN and SILENT are anagrams of each other, sharing all six letters.
  4. 4. Bank
  5. 5. Therein — T-HE-R-E-I-N: THE (1-3), HE (2-3), HER (2-4), HERE (2-5), and REIN (4-7) are all contiguous substrings.
  6. 6. Flammable / inflammable — Both words mean "capable of catching fire," a genuine quirk of English.
  7. 7. Forty — F-O-R-T-Y: F, O, R, T, Y fall in strictly ascending alphabetical order — no other spelled-out number does.
  8. 8. Stewardesses — Every letter in "stewardesses" (S, T, E, W, A, R, D) falls on the left side of a QWERTY keyboard.

Math & Logic

  1. 9. Turn switch 1 on for several minutes, then turn it off. Turn switch 2 on and immediately enter the room. The lit bulb is switch 2's. The off-but-warm bulb is switch 1's. The off-and-cool bulb is switch 3's.
  2. 10. 14 drops — Using a decreasing-interval strategy (start at floor 14, then 27, 39...), the worst case is bounded by the smallest n where n(n+1)/2 ≥ 100, which is n = 14.
  3. 11. Take the goat across first and return alone. Take the wolf across, bring the goat back. Take the cabbage across and return alone. Finally, take the goat across. — The goat crosses twice, which is the key — it's never left alone with the wolf or the cabbage.
  4. 12. 312211 — Each term describes the previous one aloud ("look-and-say"): 111221 is "three 1s, two 2s, one 1," which becomes 312211.
  5. 13. 3 weighings
  6. 14. 17 minutes — Send the two fastest (1+2) across together, send the fastest back, send the two slowest (5+10) across together, send the second-fastest back, then send the two fastest across again: 2+1+10+2+2 = 17.
  7. 15. 5 hours — The ratio of people to fences stays 1:1, so each person still needs the same 5 hours to finish their own fence.
  8. 16. The father is 40 and the son is 10. — f = 4s and f + 20 = 2(s + 20) → 4s + 20 = 2s + 40 → s = 10, f = 40. Check: in 20 years, 60 = 2 × 30.

Lateral Thinking

  1. 17. His parachute failed to open — he was skydiving.
  2. 18. They're two of a set of triplets (or more) — there's at least one other sibling from the same birth.
  3. 19. Switch to door #2 — doing so wins the car 2/3 of the time, versus only 1/3 if you stay. — The host's guaranteed reveal of a goat concentrates the original 2/3 chance that "the car is behind one of the other two doors" entirely onto the one door he didn't open. This is the classic Monty Hall problem.
  4. 20. She's a wedding officiant (like a minister or judge) — she "married" them by performing their weddings, not by being their wife.
  5. 21. He's walking, not driving — going the wrong way on foot down a one-way street isn't against the law, only driving is.
  6. 22. The poison was in the ice cubes, which hadn't melted yet when he drank his glass — by the time everyone else drank later, the ice had melted and poisoned their punch.
  7. 23. She always predicts 0–0 — which is genuinely, always the score before a match starts.
  8. 24. An umbrella — A closed ("down") umbrella fits up a chimney; an open ("up") one does not fit down a chimney.

Trivia

  1. 25. The 15th century — Gutenberg's press dates to around 1440.
  2. 26. The bat
  3. 27. Iron — From the Latin word "ferrum."
  4. 28. A murder (of crows)
  5. 29. Michelangelo
  6. 30. 2 — It's the only even prime — every other even number is divisible by 2.
  7. 31. Stagflation
  8. 32. The platypus

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