Examples for 8th grade - page 36

  1. Against each other
    Lotus_Esprit From two points A, B distant 45 km at the same time started two cars against each other at speeds 81 km/h and 67 km/h. How long does cars meet and what distance passes each of them?
  2. Sports games
    kureci_olympiada Pupils of same school participated district sports games. When dividing into teams found that in the case of the creation teams with 4 pupils remaining 1 pupil, in the case of a five-member teams remaining 2 pupils and in the case of six-members teams r
  3. Painters
    painters The first team of painters would paint bridge in 15 days, the second in 10 days. After 3 days of working together second team goes out and continue only first team. How many days took second team to finish painting the bridge?
  4. Spartakiada
    spartakiada_1 Practitioners lined up in rectangle with row with four, five or six exercisers, one always missing to full rectangle. How many exercisers were on the field, if they have estimated not been more than 100?
  5. Louvers
    zaluzie The company charges for office equipment louvers total 244 Eur. From the delivery bill is obvious that the louvers are 73 Eur expensive than their installation. What percentage of the total charged is the installation of louvers?
  6. Car rent
    car_5 Rental cars are paid a fixed daily fee plus 16 cents for each kilometer traveled. Samuel want to rent a car for a day and worked out that will pay 175 euros. When paying he got a 20% discount on the daily fee, the cost per kilometer is unchanged. Samuel th
  7. Tin with oil
    konzerva Tin with oil has the shape of a rotating cylinder whose height is equal to the diameter of its base. Canned surface is 1884 cm2. Calculate how many liters of oil is in the tin.
  8. Homework - jumps
    castle_children Sasha jumped 142 cm Peter 4 cm more than Jirka. Jirka 6 cm less than Misha. Misha 7 cm less than Filip and Filip half as much Sasha and Petr together. How far each jumped?
  9. Unknown number
    iks-icon Samuel wrote unknown number. Then he had add 200000 to the number and the result multiply by three. When it calculated he was surprised, because the result would have received anyway, if write digit to the end of original number. Find unknown number.
  10. Father and son
    family_17 Father is 48 years old, son 23. When will be the father twice older than a son?
  11. Cube wall
    cubes_16 Calculate the cube's diagonal diagonal if you know that the surface of one wall is equal to 36 centimeters square. Please also calculate its volume.
  12. Solution
    chemistry In 300 dl red solution is 154 dl red color and in 132 dl blue solution is 12 dl blue color. How many dl of red and blue dl color solution must be mixed to get a mixture of 499 dl contain 168 dl of color?
  13. Logs
    tramy The log has diameter 30 cm. What's largest beam with a rectangular cross-section can carve from it?
  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. Triangular pyramid
    trojboky_ihlan Determine the volume and surface area of a regular triangular pyramid having a base edge a=20 cm and a lateral edge b = 35 cm
  16. Bus stop
    bus_5 Determine at what time the bus leaves from the bus stop outside the village, if you know that when you leave home at 8:00 and go at speed 3 km/h, you come to a stop 9 minutes after the departure of the bus, and when you go speed at 4 km/h, you come to the
  17. Disinfecting solution
    desinfect How much distilled water is necessary to pour into 500 ml of 33% hydrogen peroxide solution to obtain 3% disinfecting solution?
  18. Arc
    angles Convert to arc measures (radians): 1367 ° Result write as a multiple of π
  19. Clock hands
    watch_3 The hands on the clock shows the time 12 hours and 2 minutes. Calculate the size of a sharp angle between clock hands three hours later.
  20. Pedestrian and the cyclist
    cyklista_1 Pedestrian and cyclist went against each from the two cities that are distant 40 km. Pedestrian started 30 minutes before the cyclist and walk an average speed of 5 km/h. What speed went cyclist when met after 120 minutes from the start of the pedestrian?

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