Trang chủ / Toán Kangaroo / Lớp 5-6

Đề thi toán Kangaroo Mỹ lớp 5-6 năm 2010

1. 3 points questions

Knowing that , which number is represented by ?





2. The number 4 is next to two mirrors so it reflects twice as shown. When the same thing happens to number 5, what do we get in the place of the question mark?





3. Small Kangaroogoes directly from Zoo to School. He counts each flower on the way. Which of the following number cannot be his result?




4. A ladder has 21 stair steps. Nick and Mike are counting stepsbut one from bottom to top and the other from top to bottom. They meet on a stair step that Nick called the 10th. What number will Mike give to the same stair step?




5. Ann has connected all the upper points to all the lower points. How many lines Ann has drawn?




6. A fly has 6 legs, while a spider has 8 legs. Together, 2 flies and 3 spiders have as many legs as 10 birds and ...




7. There are seven bars in the box. It is possible to slide the bars in the box so there will be room for one more bar. At least how many bars have to be moved?




8. A square sheet of paper has a grey in the upper side and whiteinthe lower side. Ann has divided it in nine little squareswith numbers in each vertical line segment. Along which line segments does she have to cut the paper in order to form the second picture?




9. What is the perimeter of the figure to the right(whose angles are all right angles)?




10. The following figure shows five projections of knots. Actually only one of them is really a knot, all the others just seem to be one. Which one is the knot?




11. 4 points questions

Which of the following expressions has a different value?





12. If the figure is rotated half circular turnaround F, the result is:




13. Ben has selected a number, has divided it by 7, then added 7 and finally multiplied the sum by 7. That way he comes up with the number 777. Which number did he select?




14. The numbers 1, 4, 7, 10 and 13 have to be written in the picture so that the sum of three numbers in a row equal to the sum of the three numbers in a column. What is the biggest possible sum?




15. To make a newspaper with 60 pages you need 15 sheets of paper which are on top of each other. Then they are folded together. Page 7 is missing. Which other pages are missing in this newspaper?




16. By what  can be replaced to have:
X = 2 X 2 X 3 X 3 ?




17. Using the picture to the right we can observe that 1+3+5+7 = 4 x 4. What is the value of 1 + 3 + 5 + 7 + ... + 17 + 19 + 21?




18. Ivona has drawn a flower with 5 petals. She wants to colour the flower, but she has only 2 different colours –white and black. How many different flowers can Ivona draw if she has to colour each petal using one of these 2 colours?




19. What fraction of the square is the shaded region?




20. Three identical dice are glued together. See picture. The sum of dots on opposite sides of a dice is always 7. What is the sum of dots on the sides which are glued together?




21.

5 points questions

The picture shows a balanced mobile. We neglect weights of horizontal bars and vertical strings. The total weight is 112 grams. What is the weight of the star?





22. A pizza-shop offers a basic version of pizza with mozzarella and tomatoes. One or two toppings must be added: anchovies, artichokes, mushrooms, capers. Moreover, for each pizza three different sizes are available: small, medium, large. How many different types of pizza are available ?




23. To decide who will have the last piece of Leni’s birthday cake Leni, Sarah, Hannes, Petra and Arno stand in a circular form clockwise in order of their names above. They count clockwise: KAN-GA-ROO-OUT-GOES-YOU –each syllable counts one child and the one who is caught by the YOU is out of the game. They repeat until there is only one child left. Leni can choose who starts. Who will she pick to start in order to secure that the last piece of cake stays for her best friend Arno?




24. A jeweller makes chainsby connecting identical grommets (picture 1). Proportions of grommets are shown on picture 2. What is the length of a chain which consists of 5 grommets?




25. If in the multiplication PPQ x Q = RQ5Q, the letters P, Q and R are different. P + Q + R =




26. What is the number of black cells in the figure that should be re-coloured white in order for any row and any column to contain exactly one black cell?




27. Andrea has wound some rope around a piece of wood. She rotates the wood as shown with the arrow.

Front side
What is the correct back side of the piece of wood?
Back side:




28. Ana bought a ticketwith seat number100. Bea wants to sit as close to heras possible. Only 5 tickets are available: 76, 94, 99, 104 and 118. Which one is the best?




29. All triangles must be filled using the numbers 1, 2, 3, 4. Each time a piece of the form indicated on the right picture placed on four triangles, it hides 4 different numbers. (The piece can turn around, and hence it can be placed in any position). Some numbers have already been written. What number should be written in the place of *?




30. Six-, seven-and eight-legged octopus serve the underwater king. Those who have got 7 legs always lie, but those with 6 or 8 legs, always tell the truth. One day four octopuses met.
The blue one said: «Altogether we've got 28 legs»,
the green one said: «Altogether we've got 27 legs»,
the yellow one said: «Altogether we've got 26 legs»,
the red one said: «Altogether we've got 25 legs».
What’s the colour of the octopus telling the truth?