Examples for 8th grade - page 11

  1. Pumps 3
    pump_water Two pumps of the same power fill the garden pool for 10 hours. How many of these pumps would have to use if we want to shorten the filling of the pool to four hours?
  2. Volume from surface area
    cube_3 What is the volume of the cube whose surface area is 96 cm2?
  3. Bouquet
    flowers_1 Gardener tying bouquet of flowers for 8 and none was left. Then he found that he could tying bouquet of 6 flowers and also none was left. How many have gardener flowers (minimum and maximum) if they had between 50 and 100 flowers?
  4. Three digits number
    3digit From the numbers 1, 2, 3, 4, 5 create three-digit numbers that digits not repeat and number is divisible by 2. How many numbers are there?
  5. Blueberries
    boruvky Marie earns 1.8 liters of blueberries for 1.2 hours, Peter 2.6 liters for 1.2 hours. How long have earns together one liter?
  6. Cleaners
    clean Milan would clean up the room for 2.5 hours, Eric would take 10 hours. How long they swept the room together?
  7. Word problem
    hungary-flag 384 students were on holiday in Hungary. 146 bought pizza, chips 25 pupils, 39 pupils bought soda, butter 15 pupils, 18 pupils fruits, vegetables 29 students. How much pay for all the food, if every meal cost 4.9 euros?
  8. Two cars
    cars_racing Two cars started against each other at the same time to journey long 225 km. First car went 35 km/h and second 48 km/h. What distance will be between this cars 20 minutes before meet?
  9. Apples and pears
    hrusky2 Mom divided 24 apples and 15 pears to children. Each child received the same number of apples and pears - same number as his siblings. How many apples (j=?) and pears (h=?) received each child?
  10. Strange x
    pie For what x is true ??
  11. Cube wall
    kocka Surface of first cube wall his 361 cm2. Second cube area is 30% of the surface of the first cube. Determine the length of the edge of the second cube (x).
  12. Tissues
    harmasan The store got three kinds of tissues - 132 children, 156 women and 204 men. Tissues each species were packed into boxes after the number of pieces the same for all three types (and greatest). Determine the number, if you know that every box has more than 6
  13. Coins
    mince_1 On coins found was stated that from the year 87 BC. It is right?
  14. Brothers and sisters
    family 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?
  15. Bus vs. train
    bus_vs_train Bus started from point A 25 minutes before the train started from the same place. The bus went an average speed of 41 km/h, train 67 km/h. To point B train and bus arrived simultaneously. Calculate time of train journey, if train and bus travelled the.
  16. Cube
    kocka_rubik The cube weighs 18 kg. How weight is cube of the same material, if its dimensions are 3-times smaller?
  17. Two doctors
    dr_cvach Doctor A will determine the correct diagnosis with a probability 80% and doctor B with a probability 72%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
  18. Trapezoid
    trapezoid_1 Calculate area of trapezoid ABCD with sides |AD|= 33 cm, |DC|=15 cm, |CB|=19 cm, |AB|=13 cm..
  19. Eiffel Tower
    eiffel_tower Eiffel Tower in Paris is 300 meters high, is made of steel. Its weight is 8000 tons. How tall is the tower model made ​​of the same material, if it weigh is 4.8 kg?
  20. Do you solve this?
    rectangles_4 Determine area S of rectangle and length of its sides if its perimeter is 96 cm.

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