Examples for 8th grade - page 50

  1. Sphere fall
    sphere How many percent fall volume of sphere if diameter fall 5×?
  2. Jewel
    rhombus3 Rhombus-shaped jewel have area of 86 mm2 and the edge in long 10 mm. Calculate the size of rhombus acute angle.
  3. Mr and Mrs
    clocks2_8 Mr. Calda and Mrs. Cald have a total of 139 years. How many years have when we know that Mr. Calda is 9 years older than Mrs. Cald
  4. Driver
    truck_2 The driver of the supply car reckoned that at the average speed of 72 km/h arrives to the warehouse for 1 1/4 hours. After 30 km however unintentionally drove to the gas station and have ten minutes delay. At what average speed would have to go the rest.
  5. Z7-I-4 stars 4949
    hviezdicky_mo Write instead of stars digits so the next write of product of the two numbers to be valid: ∗ ∗ ∗ · ∗ ∗ ∗ ∗ ∗ ∗ ∗ 4 9 4 9 ∗ ∗ ∗ ∗ ∗ ∗ 4 ∗ ∗
  6. Two sisters
    cd_disc Two sisters together have 54 CDs. 6/8 CDs has younger sister and is equal to 3/5 of CDs older sisters. How many CDs has each of the sisters?
  7. Price saleoff
    2digits_1 Shoes standing y euros. At first they were discounted by 12% and then 50% of the new amount. After this double cheapening the cost was exactly 22 euros. Determine the original price of shoes.
  8. The deposit
    money_13 Deposit has been placed for one year at an annual rate of 4.5%. After the added interst amount rose to € 2,612.5. Determine initial deposit.
  9. ATC camp
    camp The owner of the campsite offers 79 places in 22 cabins. How many of them are triple and quadruple?
  10. Potatoes bags
    vrece_zemiakov I have three bags with 21 kg potatoes. The first bag is 5.5 kg more than in the second bag and the third is 0.5 kg more than in the second bag. Determine how many kgs of potatoes is in each bag.
  11. Circumscribed circle to square
    kruznice Find the length of a circle circumscribing a square of side 10 cm. Compare it to the perimeter of this square.
  12. Middle segment
    priecka In a triangle ABC with the side /AB/ = 24 cm is constructed middle segment /DE/ = 18 cm parallel to the side AB at a distance 1 cm from AB. Calculate the height of the triangle ABC to side AB.
  13. Angles of a triangle
    triangles_9 In the triangle ABC, the angle beta is 15° greater than the angle alpha. The remaining angle is 30° greater than the sum of the angles alpha and beta. Calculate the angles of a triangle.
  14. Roses
    zahon-s-ruzemi On the large rosary was a third white, half red, yellow quarter and six pink. How many roses was in the rosary?
  15. Unknown number
    5nums_1 Determine the unknown number, which double of its fourth square is equal the fifth its square.
  16. Triangle KLB
    rovnostranny_trojuholnik It is given equilateral triangle ABC. From point L which is the midpoint of the side BC of the triangle it is drwn perpendicular to the side AB. Intersection of perpendicular and the side AB is point K. How many % of the area of the triangle ABC is area o
  17. Boots
    vysoke-cizmy Master shoemaker has three apprentices. First do one pair of boots for two days, second for 1 day, third on 1.5 day. If they worked together, for how long it would take made a couple of boots?
  18. Cyclist
    cyklista Cyclist rode two-fifths of the way the first day. The second day drove 5 km less while traveled three-eighths of route. How many kilometers does he have to finish target?
  19. Workers 2
    delnik Worker dug the trench for 7 hours, another worker for 10 hours. They recruited to work even one worker more. Digging should be done for 2 hours. For how long would dig third worker alone?
  20. Weights
    vahy_1 Marry and John together weighing 49 kg. Their weights are in ratio 1:6. Determine their weights.

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