Logic Puzzles for Kids: 20 Deduction Puzzles with Worked Answers on Riddlepedia
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Logic Puzzles for Kids: 20 Deduction Puzzles with Worked Answers

20 riddles · tap Hint or Answer to reveal

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Logic puzzles are detective work. You get a handful of clues, and each one rules something out, until only one answer is left standing. No trick words, no outside facts: everything you need is in the puzzle. That makes them perfect for kids, because the answer is never a lucky guess. You can always prove it.

These 20 logic puzzles for kids go from three-clue warm-ups to a mini “Einstein puzzle” with three houses. Every answer is worked out step by step, so kids can check their thinking, not just their result. For the medium and tricky puzzles, a pencil and a quick grid (names down the side, choices across the top, an X for “no” and a check for “yes”) makes everything easier.

Easy Logic Puzzles

Ava, Ben and Cal each eat a different fruit: an apple, a banana or a cherry. Ava doesn’t eat apples or bananas. Ben doesn’t eat apples. Who eats which fruit?

Hint
Start with Ava. She has only one fruit left.
Answer
Ava has the cherry, Ben the banana and Cal the apple. Ava can’t have the apple or the banana, so she has the cherry. Ben can’t have the apple, so he has the banana, and the apple goes to Cal.

A red house, a blue house and a green house stand in a row. The red house is not in the middle. The green house is somewhere to the right of the red house. The blue house is not on the right end. What is the order from left to right?

Hint
If red isn’t in the middle, it’s on an end. Which end leaves room for green on its right?
Answer
Red, blue, green. Red must be on an end, and green is to its right, so red is on the left. Blue isn’t on the right end, so blue is in the middle and green is on the right.

Mia, Noah and Owen each have one pet: a hamster, a parrot or a rabbit. The rabbit’s owner has the shortest name. Noah doesn’t have the parrot. Who has which pet?

Hint
Count the letters in each name.
Answer
Mia has the rabbit, Noah the hamster and Owen the parrot. Mia (3 letters) has the shortest name, so she owns the rabbit. Noah can’t have the parrot, so he has the hamster, and Owen gets the parrot.

Ella is older than Finn. Finn is older than Gus. Hana is younger than Gus. Who is the youngest?

Hint
Write the names in a line from oldest to youngest.
Answer
Hana. The order from oldest to youngest is Ella, Finn, Gus, Hana.

Jay, Kim and Liv ran a race, and nobody tied. Kim didn’t win, and she wasn’t last. Liv finished after Jay. In what order did they finish?

Hint
If Kim didn’t win and wasn’t last, where did she finish?
Answer
Jay, Kim, Liv. Kim must be 2nd. Jay and Liv take 1st and 3rd, and since Liv finished after Jay, Jay won and Liv came 3rd.

Pia, Quin and Rae each have a lunch box: red, yellow or purple. Rae’s lunch box is the color of a ripe banana. Pia’s lunch box isn’t red. What color is each lunch box?

Hint
Start with the clue that tells you a color straight away.
Answer
Rae’s is yellow, Pia’s is purple and Quin’s is red. Rae’s is yellow like a banana. Pia’s isn’t red, so it’s purple, and red is left for Quin.

Dan, Eva and Fay have birthdays in March, July and December. Dan’s birthday is in the last month of the year. Eva’s birthday comes earlier in the year than Fay’s. Whose birthday is in which month?

Hint
Dan is easy. Then put the other two months in calendar order.
Answer
Dan in December, Eva in March and Fay in July. December is the last month, so it’s Dan’s. March comes before July, so Eva has March and Fay has July.

Medium Logic Puzzles

Ada, Ben, Cy and Di sit in four seats in a row. Ben sits at one end. Cy sits right next to Ada, on her right. Di does not sit next to Ben. Ben sits somewhere to the left of Di. What is the order from left to right?

Hint
Ben is at an end and has someone to his right, so which end is he on?
Answer
Ben, Ada, Cy, Di (from left to right). Ben is at an end with Di to his right, so Ben is in seat 1. Di can’t sit next to him, so seat 2 is not Di. Ada and Cy sit together with Cy on the right, so they take seats 2 and 3, and Di gets seat 4.

Ivy, Jon and Kai each own a different pet (a cat, a dog or a fish) and each has a different favorite color (red, green or blue). The person who loves green owns the dog. Ivy’s pet lives in water. Kai doesn’t like green. Kai’s favorite color is the color of a strawberry. Who owns which pet, and who likes which color?

Hint
Use the green-and-dog clue together with Kai’s clue.
Answer
Ivy fish/blue, Jon dog/green, Kai cat/red. Ivy’s pet lives in water, so it’s the fish. Kai doesn’t like green, so he can’t own the dog, which leaves him the cat and Jon the dog (and green). Kai likes strawberry red, so blue is left for Ivy.

Somebody ate the last cookie. Ana says, “Ben ate it.” Ben says, “I didn’t eat it.” Cora says, “I didn’t eat it.” Only one of them is telling the truth. Who ate the cookie?

Hint
Try each person as the cookie eater and count how many true statements you get.
Answer
Cora. If Ana ate it, Ben and Cora would both be telling the truth. If Ben ate it, Ana and Cora would both be telling the truth. If Cora ate it, only Ben’s words are true, which is exactly one.

A lock has a 3-digit code with three different digits. The first digit is 2 more than the last digit. The middle digit equals the first and last digits added together. All three digits add up to 12. What is the code?

Hint
Try small numbers for the last digit and build the rest from it.
Answer
  1. With 2 as the last digit, the first is 4 and the middle is 4 + 2 = 6, and 4 + 6 + 2 = 12. A last digit of 1 gives a sum of 8, and a last digit of 3 gives 16, so 2 is the only one that works.

Four books are stacked in a pile: red, blue, green and yellow. The green book is on the bottom. The yellow book is directly on top of the red book. The blue book is not on top. What is the order from top to bottom?

Hint
Yellow and red are stuck together. Where can that pair go?
Answer
Yellow, red, blue, green. Green is on the bottom. If yellow and red took the 2nd and 3rd spots, blue would have to go on top, which isn’t allowed. So yellow and red are the top two, and blue is third.

On Planet Zog, Zogs in blue hats always tell the truth and Zogs in red hats always lie. You meet a Zog in the dark and can’t see its hat. You ask, “Do you always lie?” What will it answer?

Hint
Work out what a truth-teller would say, then what a liar would say.
Answer
“No,” every time. A truth-teller doesn’t always lie, so it truthfully says no. A liar does always lie, so the true answer is yes, and it lies and says no.

A box holds 5 red, 4 blue and 3 green crayons. With your eyes closed, how many crayons must you take out to be sure you have at least one green crayon?

Hint
Imagine the worst luck possible.
Answer
  1. With the worst luck, you’d pull out all 5 red and all 4 blue crayons first. The very next one, the 10th, has to be green.

Three apples weigh the same as one melon. Two melons weigh the same as one pumpkin. How many apples weigh the same as one pumpkin?

Hint
Swap each melon for apples.
Answer
  1. One pumpkin weighs the same as 2 melons, and each melon is 3 apples, so 2 × 3 = 6 apples.

Tricky Logic Puzzles

Three houses stand in a row. Each is a different color (red, white or blue), has a different pet (a cat, a dog or a fish), and its owner drinks something different (milk, juice or water). The owner of the middle house drinks milk. The red house is directly to the left of the blue house. The cat’s owner drinks water. The fish lives in the white house. The juice drinker lives directly to the left of the dog’s house. What color is the dog’s house, and what does the fish’s owner drink?

Hint
The red-blue pair can sit in only two places. Try both and see which one breaks a clue.
Answer
Red house; juice. The cat’s owner drinks water, so the cat isn’t in the middle (that owner drinks milk). If the order were red, blue, white, the fish would be on the right and the cat on the left, which leaves the dog in the middle with juice on the right: but juice has to be left of the dog. So the order is white, red, blue: fish and juice in the white house, dog and milk in the red middle house, cat and water in the blue house.

One of four children broke a vase. Exactly one of them is lying. Amy says, “Ben did it.” Ben says, “Dot did it.” Cal says, “I didn’t do it.” Dot says, “Ben is lying.” Who broke the vase?

Hint
Ben and Dot can’t both be telling the truth. That means the one liar is one of them.
Answer
Ben. Ben and Dot contradict each other, so the liar is one of them, and Amy and Cal tell the truth. Amy’s true statement says Ben did it. Check it: Ben lies, Dot is right that Ben is lying, and Cal really didn’t do it.

A farmer must take a fox, a chicken and a bag of grain across a river. His boat holds him and only one of the three at a time. If he leaves the fox alone with the chicken, the fox eats the chicken. If he leaves the chicken alone with the grain, the chicken eats the grain. How does he get everything across safely?

Hint
Sometimes the farmer has to bring something back with him.
Answer
He takes the chicken first. Take the chicken over and return alone. Take the fox over and bring the chicken back. Leave the chicken, take the grain over and return alone. Finally, take the chicken over again.

Polly the parrot lies on Mondays, Tuesdays and Wednesdays and tells the truth on every other day. Today Polly says two things: “I was lying yesterday” and “Today is not a weekend day.” What day is it?

Hint
Check the first sentence against all seven days, then use the second sentence to choose.
Answer
Thursday. “I was lying yesterday” only fits two days. On Monday she lies and yesterday she told the truth, so the sentence is false, which a liar would say. On Thursday she tells the truth and yesterday she lied, so it’s true. On Monday, “Today is not a weekend day” is true, and a liar can’t say it, so it must be Thursday.

Lea, Kai and Max are siblings. Kai is twice as old as Lea. Max is 2 years older than Kai. Their ages add up to 22. How old is each of them?

Hint
If Lea is 1 “part,” Kai is 2 parts and Max is 2 parts plus 2 years.
Answer
Lea is 4, Kai is 8 and Max is 10. Five parts plus 2 years is 22, so five parts is 20 and one part is 4. Check it: 4 + 8 + 10 = 22.

How to Use These Logic Puzzles

  • Grid it out: in class, draw a 3 × 3 grid on the board for the easy puzzles and solve one together, marking an X for every “no.” Then let pairs try the next one on their own.
  • Prove it, don’t guess it: award one point for the right answer and a bonus point for explaining which clue rules out each wrong option. That habit is what makes logic puzzles worth doing.
  • Party detective game: read the vase or cookie puzzle aloud as a mystery, give each guest a “suspect card,” and let the group question the suspects before anyone guesses.
  • Make your own: have kids write a three-person, three-pet puzzle for a partner. The test: can the partner solve it, and is there only one answer?

Ready for harder ones? Try our logic riddles, the cases in our detective riddles or these number riddles.