Examples for 8th grade - page 51

  1. The pot
    hrniec_1 Diameter of the pot 38 cm. The height is 30 cm. How many liters of water can fit in the pot?
  2. Passenger car and truck
    2cars From Kutna Hora left at 11:00 clock a truck at 60 km/h. At 12:30 behind him started passenger car at average speed 80 km/h. At what time and how far from Kutna Hora overtake a passenger car truck?
  3. Quadrant
    quadrants In what quadrant is a -1165° angle?
  4. Perimeter of circle
    thalet_1 Calculate the circumference of described circle to the triangle with sides 9,12,15 cm.
  5. Mean
    integrales if the mean of the set of data 5, 17, 19, 14, 15, 17, 7, 11, 16, 19, 5, 5, 10, 8, 13, 14, 4, 2, 17, 11, x is -91.74, what is the value of x?
  6. The farmer
    kombajn The farmer harvested 840 tons of grain in 2006, which was 44% less than in 2005, and one-fifth more than in 2004. How many tons of grain harvested in years 2005 and 2004?
  7. Rhombus A2p
    kosostvorec Rhombus area is 13 cm2 and its height is 5cm long . Determine a perimeter of this rhombus.
  8. Grandmother's clocks
    kukuckove-hodiny Grandmother's clock is late every hour by half a minute. Grandmother it by set exactly at 8.00 am. How many hours will show after 24 hours.?
  9. Pine
    trees How much of a mixed forest rangers want to cut down, if their head said: "We only cut down pine trees, which in our mixed forest 98%. After cut pine trees constitute 94% of all trees left."
  10. Stone
    kamen When Peter threw stone in a box of water he discovered that the water level has risen by 6 cm. The box has a cuboid shape, the bottom has dimensions of 24 cm and 14 cm, height is 40 cm. What volume has a stone?
  11. Tower model
    tower Tower height is 300 meters, weight 8000 tons. How high is the model of the tower weight 1 kg? (State the result in the centimeters). The model is made from exactly the same material as the original no numbers need to be rounded. The result is a three-digi
  12. Wheel
    wheel_1 What is the wheel diameter if on the 0.38 km track turns 128 times?
  13. Water pool
    water What water level is in the pool shaped cuboid with bottom dimensions of 25 m and 10 meters, when is 3750hl water in the pool.
  14. 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.
  15. 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?
  16. Legs
    zidle In the room are four-legged chairs, three-legged stool, and all are sitted with (one) people. I counted all the leg room and there were a total of 39. How many are there chairs, stool and people?
  17. Scale of the map
    meritko Determine the scale of the map if the actual distance between A and B is 720 km and distance on the map is 20 cm.
  18. Scouts
    skauti_2 Scouts purchased for camp cans two types total cost 1460 CZK. First cans were for CZK 32 and second for 25 CZK. How many cans purchased each type?
  19. Euros
    fractal_1 Michal, Peter, John and Lenka got together 2,400 euros. They share an amount in ratio 2:6:4:3. How many got each of them?
  20. Profits
    podnikavec Two members will make profit 52 000, - EUR. The forst earned 8% more and the second 10% more and thus earned together 56 700, - EUR. How many will initially each earn?

Do you have an interesting mathematical word problem that you can't solve it? Enter it, and we can try to solve it.



To this e-mail address, we will reply solution; solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...