# Examples for 7th grade (seventh) - page 23

1. Diagonal Can be a diagonal of diamond twice longer than it side?
2. A family A family of four pays for garbage collection per year 1800 Kč. How many crowns a year the waste company get from the house where lives 93 people?
3. Unknown integer Find the smallest integer that: divided by 2, the remainder is 1 divided by 3 the remainder is 2, divided by 4 remainder is 3, ... divided by eight reminder is 7, by 9 reminder is 8.
4. Milimeters The pool is 6 meters long, 3 meters wide and the water in it is filled with water to a height 1.7 m. When John jumped into it and completely submerged, the level has risen by 5.4 mm. How much weight John when we know that one liter of the human body weighs
5. Minute-hand How long distance will travel a large (minute) hand on the clock for 47 minutes, if its length is 43 cm?
6. Bricks wall There are 5000 bricks. How high wall thickness of 20 cm around the area which has dimensions 20 m and 15 m can use these bricks to build? Brick dimensions are 30 cm, 20 cm and 10 cm.
7. Painting Jožko with Fero painted the bench for four hours. How many hours would take work if four friends help him?
8. Class 8.A Three quarters of class 8.A went skiing. Of those who remained at home one third was ill and the remaining six were on math olympic. How many students have class 8.A?
9. Cows 20 cows has food for 60 days. We reduce the dose to two-thirds for 18 cows. How many days will be fed?
10. Knight Knight passed 13 km long track in 26 minutes, what was his average speed?
11. Brothers and sisters Lenka has as many brothers as sisters. Her brothers have twice as many sisters as brothers. How many brothers and sisters are in the family?
12. Czech crown salary The monthly salary of the employee is CZK 10,800. In the course of the year the bulk salary increased by CZK 500. Calculate which month (1 ... 12) was increased if its annual income was 133,600 CZK.
13. Garden Rectangular garden has a length 99 m and width 84 m. Calculate how many m2 will decrease its area if land by ornamental fence with width 30 cm.
14. Clock hands The hands on the clock shows the time 12 hours and 2 minutes. Calculate the size of a sharp angle between clock hands three hours later.
15. Diagonal Can a rhombus have the same length diagonal and side?
16. Unknown number Samuel wrote unknown number. Then he had add 200000 to the number and the result multiply by three. When it calculated he was surprised, because the result would have received anyway, if write digit to the end of original number. Find unknown number.
17. Cylinder - h2 Cylinder volume is 2.6 liters. Base area is 1.3 dm2. Calculate the height of the cylinder.
18. Pedestrian and the cyclist Pedestrian and cyclist went against each from the two cities that are distant 40 km. Pedestrian started 30 minutes before the cyclist and walk an average speed of 5 km/h. What speed went cyclist when met after 120 minutes from the start of the pedestrian?
19. Square If we increase one side of square by its one-half then square perimeter increase by 10 cm. What is the side of the square?
20. Annulus Two concentric circles form an annulus of width 10 cm. The radius of the smaller circle is 20 cm. Calculate the content area of annulus.

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