Examples for 8th grade - page 33

  1. Raspberries
    maliny_2 Dano had 20 raspberries. John had 90% more raspberries than Dano. Determine how many raspberries have Dano and Juraj together.
  2. Cylinder twice
    valec_3 If the radius of the cylinder increases twice, and the height is reduced twice, then the volume of the cylinder increases (how many times?):
  3. Four classses
    think Students of all 7, 8 and 9 classes in one school may take up 4,5,6 and 7 abreast and nobody will left. How many is the average count of pupils in one class if there are always four classes each grade?
  4. Bronze, tin and copper
    zvon Bronze is an alloy of tin and copper. An alloy of 10% tin and 90% copper is Gunmetal. If it contains 20% tin and 80% copper, it is bell metal. How many tons of molten bell metal and how many tons of copper is needed to make 100 tons of Gunmetal?
  5. Workers
    zamkova_dlazba Ten workers must pave road street for 22 working days. After four days were for speeding up work added two more workers. a) After how many work days now workers completes the paved road? b) How many working days it took a total paved road?
  6. Gearing
    prevod Gearing consists of two wheels, one is 88 and second 56 teeth. How many times turns smaller wheel to fit the same teeth as in the beginning? How many times will turn biggest wheel?
  7. Painter 3
    painter_2 Dad want to paint wall high 250 cm wide and 230 cm with wallpaper. How many meters must buy wallpaper if wallpaper width is 60 cm?
  8. Roof tiles
    Lichobeznik_strecha The roof has a trapezoidal shape with bases of 15 m and 10 m, height of roof is 4 meters. How many tiles will need if on 1 m2 should be used 8 tiles?
  9. Three friends
    pizza_4 Divide 570 euros to three friends so that first will get 50 euros less than the second and third twice more than the first. How many euros will get everyone?
  10. The book
    1438931371257-1350799500 If one day you read p pages, you will read the book 24 days. If you read each day 10 pages more, you would read a book in 16 days. How many pages have the book?
  11. Stock
    frac Enterprise sold 7/12 of their products to foreign markets and 2/5 of the remainder sold at home. How many % of the products is still in stock?
  12. Stairs
    schosy Between adjacent levels are 15 stairs. If step will be 1.2 cm lower there would be 16 stairs. What is the stair height?
  13. Alloy
    hlinik_slitina The first alloy is a mixture of two metals in the ratio 1:2, the second is a mixture of same metals in the ratio 2:3. At what ratio we have these two alloys put into the furnace to obtain a new metal alloy with ratio 17:27? (All three ratios correspond to.
  14. Complementary angles
    angles_2 Two angles are complementary. If one angle measures 49°, what is the measure of the second angle?
  15. Isosceles III
    demos The base of the isosceles triangle is 24 cm area 416 cm2. Calculate the perimeter of this triangle.
  16. Fertilizer
    okurky Mr. Gherkin use for fertilization 9% solution of fertilizer. 7 liters of it still left. How much water must be added to the solution to make only 5% solution?
  17. Train
    High-Speed-Train A passenger train traveled for 4 hours 136 km. 2.7 hours after its departure started fast train and caught it on 324 km. How many km/h is different its average speeds?
  18. Squaring the Circle
    SquareCircle Calculating side of the square with the same area as the circle of radius 18.
  19. Hands
    soviet_watch The clock shows 12 hours. After how many minutes will agle between hour and minute hand 80°? Consider the continuous movement of both hands hours.
  20. Right triangle
    triangles_1 Right triangle ABC with side a = 16 and the area S = 80. Calculate the length of the remaining sides.

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