Interesting Mathematics

The tasks of the Latvian team.

1. 5 blue tits and 7 sparrows were sitting on a branch. 6 birds flew away. Did any of the sparrows fly away?

2. Marina had one whole apple, two halves and 4 quarters of an apple. How many apples did she have all together?

3. 60 pages of a book are 1 cm thick. How thick is the book if there are 240 pages in it?

4. 3 candles were burning in the room. One of them went out. How many candles were there after all?

5. Two fathers and two sons ate 3 patties. How many patties did each of them eat?

6. One log was cut into 4 parts. It was spent 2 minutes to cut out each part. How much time was it spent to cut out all 4 parts of the log?

7. It doesn’t know itself what it wants: sometimes it decreases, sometimes it increases.

8. Its sides go to different destinations.

9. A stork standing on 2 legs weighs 2 kg. How much does a stork standing on 1 leg weigh?

10. A pair of horses made 20 km in a race. How many km did each of the horses make?

11. How many ends do two sticks and a half of a stick have?

12. There are 10 fingers on the hands. How many fingers are there on 10 hands?

13. A doctor prescribed a patient to have 3 injections every half an hour. The first injection was given at 8 o’clock. At what time will the last injection be given?

14. A pine is higher than an asp, an asp is higher than a spruce. What is shorter: a pine or a spruce?

15. A pear costs two times than an apple. What is more expensive: 8 apples or 4 pears?

16. The brother is 7 years old, but the sister is five. How old will be the sister when the brother will be 10 years old?

17. There were seven candles lighting. Two candles were snuffed out. How many candles are left?

18. There are five sons. Everyone of them has one sister. How many children are there in the family?

19. Name the line that has a beginning, but doesn’t have any end.

20. Name the figure that has no angles.

21. After the walk John told: at the lake I saw 1 bee, 3 geese, 2 ducks, 1 lark and 4 dragonflies. How many birds did he see?

22. Julia was asked: “How many students are there in your class?” Julia answered: “This number is smaller than 26, but bigger than 23 and is even.” How many students are there in Julia’s class?

23. Erudite and Mrs. Brain have eaten a box of chocolates and are counting how many chocolates are left. Erudite said: “If you give me one chocolate from your box, then we will be the same amount of chocolates.” Mrs. Brain looked into Erudite’s box and replied: “But you have already eaten all your chocolates.” How many chocolates are left in Mrs. Brain’s box?