Examples for 8th grade - page 14

  1. Climb
    aircraft_ascend For horizontal distance 3 km road rise by 5.4 m. Calculate the road pitch in ‰ (permille, parts per thousand).
  2. Double percent
    percents What is 70% of 70% of 10500?
  3. Unknown x
    UnknownX If we add to unknown number 72, then divide by 2 and then subtract 29, we get back an unknown number. What is this unknown number?
  4. Train and car
    car_vs_train The train and the car started at a constant speed to journey. When the train travels 78 km, the car travels 64 km. How many km travels the train when the car travels 78 km?
  5. Class
    children_2 In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class?
  6. Swimming pool 4
    bazen_1 The pool shaped cuboid measuring 12.5 m × 640 cm at the bottom is 960hl water. To what height in meters reaches the water level?
  7. Buses
    regiojet Buses Ikarus and Karosa simultaneously started at 11:00 from the final station. Ikarus is returned to the station after 30 minutes. Karosa after 45 minutes. At what time both buses again returned to the station?
  8. Gasholder
    gas_holder The gasholder has spherical shape with a diameter 23 m. How many m3 can hold in?
  9. Waiting room
    fly In the waiting room are people and flies. Together they have 15 heads and 50 legs (fly has 6 legs). How many people and flies are in the waiting room?
  10. Hurry - rush
    bus_3 At an average speed 10 km/h I will come from the school to the bus stop for 29 minutes. How fast I need to go if I need to get to the bus stop in 21 minutes?
  11. Pizza
    pizza_1 A school survey found that 9 out of 16 students like pizza. If 5 students are chosen at random, what is the probability that all 5 students like pizza?
  12. Five tractors
    tractor_1 Five tractors plow field in 4.8 hours. How long plow this field if after 1.5 hours of work two tractors went to a different field?
  13. Air
    air_room_people Room is 26.2 m long, 23.4 dm wide and 628 cm high. How many people can simultaneously be in this room if for hygiene reasons is calculated 5100 dm3 of air per person?
  14. Square
    1square Calculate area of the square with diagonal 70 cm.
  15. Chess
    sachovnica How many ways can select 3 fields on classic chess board with 64 fields, so that fields don't has the same color?
  16. Parachutists
    parasutism Parachutists during freefall firstly held in groups of 4, then of 6, then 9, 12 and finally of 18 members. How many parachutists jump at least should be, if at each group must all be involved.
  17. Arm
    arm Calculate the length of the arm r of isosceles triangle ABC, with base |AB| = 16 cm and a height v=10 cm.
  18. Ladislav in Amsterdam
    jakob3 Ladislav was reward and went to conference in Amsterdam. Conferense fee was € 2184. Calculate how many books Ladislav could buy at the price of 42 and 28 euros if he don't want fill whole home library and he can buy only 63 books?
  19. Gloves
    rukavice I have a box with two hundred pieces of gloves in total, split into ten parcels of twenty pieces, and I sell three parcels. What percent of the total amount I sold?
  20. Apples 2
    jablko James has 13 apples. It has 30 percent more apples than Sam. How many apples has Sam?

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