Brain teasers with answers for ages 11 to 14

20 questions

1. All Bloops are Razzies, and all Razzies are Lazzies. Are all Bloops definitely Lazzies?

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   Yes. Every Bloop is a Razzie, and every Razzie is a Lazzie, so every Bloop must be a Lazzie too.

2. What letter comes next? A, B, B, C, C, C, D, D, D, D, ?

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   E. Each letter appears as many times as its position: A once, B twice, C three times, D four times. D is done, so E starts next.

3. Finger is to hand as toe is to what?

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   Foot. Fingers are part of a hand; toes are part of a foot.

4. A clock strikes 6 times at 6 o’clock and takes 5 seconds to do it. How long does it take to strike 3 times?

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   2 seconds. 6 strikes have 5 gaps of 1 second. 3 strikes have 2 gaps, so 2 seconds.

5. What is the sum of the angles inside a quadrilateral?

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   360°. A quadrilateral splits into two triangles: 2 × 180° = 360°.

6. What is the smallest number that leaves a remainder of 1 when divided by 2, 3, 4 or 5?

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   61. The LCM of 2, 3, 4 and 5 is 60, so the answer is 60 + 1 = 61.

7. What number comes next? 3, 4, 7, 11, 18, 29, ?

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   47. Each number is the sum of the two before it: 18 + 29 = 47.

8. Which one is the odd one out: kidney, liver, lung, femur?

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   Femur. Kidneys, liver and lungs are organs. The femur is a bone (in your thigh).

9. Kilogram is to weight as litre is to what?

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   Volume. A kilogram measures weight; a litre measures volume (how much space a liquid takes up).

10. A snail climbs 3 m up a 10 m wall each day and slips back 2 m each night. On which day does it reach the top?

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    Day 8. After 7 days and nights it is at 7 m. On day 8 it climbs 3 m and reaches 10 m before slipping.

11. What is 1.5 + 2.75?

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    4.25. 1.5 + 2.75 = 4.25.

12. What is the area of a triangle with a base of 10 cm and a height of 6 cm, in square centimetres?

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    30. Area = ½ × base × height = ½ × 10 × 6 = 30.

13. What number comes next? 729, 243, 81, 27, ?

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    9. Each number is divided by 3: 27 ÷ 3 = 9.

14. Which one is the odd one out: hexagon, pentagon, octagon, sphere?

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    Sphere. Hexagons, pentagons and octagons are flat polygons. A sphere is a 3D shape.

15. Water is to ice as liquid is to what?

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    Solid. When water freezes it becomes ice, which is a solid.

16. A man looks at a photo and says, “Brothers and sisters I have none, but that man’s father is my father’s son.” Who is in the photo?

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    His son. “My father’s son” with no brothers is the man himself, so the photo shows his son.

17. How many lakhs make one crore?

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    100. 1 crore = 1,00,00,000 = 100 lakh.

18. How many prime numbers are there between 1 and 20?

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    8. 2, 3, 5, 7, 11, 13, 17 and 19: that’s 8.

19. What number comes next? 1000, 100, 10, ?

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    1. Each number is divided by 10: 10 ÷ 10 = 1.

20. Which word is the odd one out: knight, knee, knife, kite?

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    Kite. Knight, knee and knife all start with a silent K. In “kite”, you hear the K.