# Examples for 7th grade (seventh) - page 55

1. Donuts In the dining room at one table sit Thomas, Filip and Martin. Together they eat 36 donuts. How many donuts eaten everyone, when Filip ate twice as much as Thomas and Martin even half over Filip?
2. Pumps 5 5 pump pumped in 3 hours 1800 hl of water. How many hectoliters of water pumped 4 equally powerful pumps in 6 hours?
3. Cube 2 How many times will increase if the surface area of the cube if we triple length of its edge?
4. Joshka Joshka had € 15. Mama took him 15%. How many had left?
5. Buttons Shirt has 6 buttons, blouse has 4 buttons. All buttons are 176. Shirts and blouses are together 36. How many are the shirts and blouses?
6. Unknown number 24 f we add 20, we get 50% of its triple. What is this unknown number?
7. Circle from string Martin has a long 628 mm string . He makes circle from it. Calculate the radius of the circle.
8. Decide The rectangle is divided into seven fields. On each box is to write just one of the numbers 1, 2 and 3. Mirek argue that it can be done so that the sum of the two numbers written next to each other was always different. Zuzana (Susan) instead argue that.
9. Percentage - fractions About what percentage we must increase number 1/6 to get number 1/3?
10. Charles Bridge Charles Bridge was 15 times older than Frantův bridge from 1900 in 1931. How old is the Charles Bridge?
11. Wood lumber Wooden lumber is 4 m long and has a cross section square with side 15 cm. Calculate: a) the volume of lumber b) the weight of the lumber if 1 m3 weighs 790 kg
12. Perpetrator The perpetrator is a number that is smaller than the number 80. It is a multiple of five and it is odd. If we added up the tens and ones of this number we get number 8.
13. Tank To cuboid tank whose bottom has dimensions of 9 m and 15 m were flow 1080 hectoliters of water. This was filled 40% of the tank volume. Calculate the depth of the tank.
14. Circle - simple Calculate the area of a circle in dm2, if its circumference is 31.4 cm.
15. Trio 2 Decide whether trio of numbers is the side of a right triangle: 26,24,10.
16. 15 number What number is smaller (greater) by 15 than its half?
17. Common cylinder I've quite common example of a rotary cylinder. Known: S1 = 1 m2, r = 0.1 m Calculate : v =? V =? You can verify the results?
18. 2d shape Calculate the content of a shape in which an arbitrary point is not more than 3 cm from the segment AB. The length of the segment AB is 5 cm.
19. Tank How many minutes does it take to fill the tank to 25 cubic meters of water filled 150hl per hour?
20. Pumps Five pumps pumped 1,800 hl of water for 3 hours. How many hectoliters of water pump same two powerful pumps for six hours?

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