# Examples for 8th grade - page 38

1. Pot Calculate the height of 3 liter pot with shape cylinder with a diameter of 10 cm.
2. Clocks What distance will describe the tip of minute hand 6 cm long for 20 minutes when we know the starting position with finally enclose hands each other 120°?
3. Glass Peter broke the window glass with size 110 cm and 90 cm. 1 square meter of glass costs 11 USD. How much money is need to pay for a new glass?
4. Scouts Three scouts went on a three day trip. The second day went 4 km more than the first day. The third day went two times less than the first day. They went along 54 km. How many kilometers went every day together?
5. Cubes Most how many cubes with an edge length of 5 cm may fit in the cube with the inner edge of 0.4 m?
6. Bases The length of the bases trapezium are in ratio 4:5. Length of midline is 15. How long are the bases of a trapezoid?
7. Journey Charles and Eva stands in front of his house, Charles went to school south at speed 5.4 km/h, Eva went to the store on a bicycle eastwards at speed 21.6 km/h. How far apart they are after 10 minutes?
8. Three-digit numbers How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?
9. Equation with fractions Solve equation: ? It is equation with fractions.
10. Cuboid aquarium Cuboid 25 times 30 cm. How long is third side if cuboid contains 30 liters of water?
11. Pool 2 The first supply by the pool fill for five hours and the second fill for six hours, drain should be drained for 15 hours. For how many hours the pool is full, when we open both inlet now and outlet open two hours later?
12. Pocket Mirka spent on a trip for gifts half pocket. For the third remain money bought a bagel. Six euros left her. How many euros had Mirka in pocket?
13. Acreage What acreage has a rectangular plot whose diagonal is 34 meters long and one side has a length of 16 meters. ?
14. Similarity Rectangle ABCD has dimensions of 7 cm and 6 cm. Rectangle PQRS has dimensions 14 cm and 12 cm. Determine coefficient of the similarity k of the rectangles, if they aren't similar enter zero as the coefficient of similarity.
15. Sheep Shepherd tending the sheep. Tourists asked him how much they have. The shepherd said, "there are fewer than 500. If I them lined up in 4-row 3 remain. If in 5-row 4 remain. If in 6-row 5 remain. But I can form 7-row." How many sheep have herdsman?
16. Hop-garden The length of the rectangular hop garden Mr. Smith increased by 25% and its width by 30%. What is the percentage change in area of hop garden?
17. Word problem 395 students were on holiday in Hungary. 110 bought pizza, chips 21 pupils, 26 pupils bought soda, butter 18 pupils, 12 pupils fruits, vegetables 29 students. How much pay for all the food, if every meal cost 5.5 euros?
18. Trough How many liters of water per second can go via trough, which has a cross section of semicircle with radius 2.5 m and speed of water is 147 cm per second?
19. Window Peter demolish box hole in the wall for window frame 147×51 cm. When they came masters fitted frame and window will be found that glass is 13.3 cm from the hole in each direction. Calculate how much percent less light enters the window than hole?
20. Vinegar What percentage vinegar we get if we mix 1 if dm³ eight percent vinegar with 1.5 dm³ six percent vinegar?

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