Examples for 8th grade - page 41

  1. Daughters
    family_3 The man conducting the census asks a woman to age of three daughters. Woman says when multiply the age getnumber 72; if their ages add up, get a number of our house, as you see. The man says: That is not enough to calculate their ages. She says: my oldes
  2. Motion 2
    motion2 At 10 o'clock started from place A car speed at 90 km/h. 20 minutes after started from the place B at speed 60 km/h another car. Distance places A and B is 120 kilometers. What time and where they meet?
  3. For thinkings
    glass_cubes The glass cube dive into the aquarium, which has a length of 25 cm, width 20 cm and height of 30 cm. Aquarium water rises by 2 cm. a) What is the volume of a cube? b) How many centimeters measure its edge?
  4. Aircrafts
    boeings Above the town hall tower flew the plane with constant speed 508 km/h and 15 minutes later the second plane at speed of 651 km/h. How long and how far from the town hall will be aircrafts caught up?
  5. Nuts
    nuts How many we must have at least nuts if we can equally divide it to 10 children, 14 children or 19 children and any nut left?
  6. Tetrahedral pyramid
    jehlan_3 It is given a regular tetrahedral pyramid with base edge 6 cm and the height of the pyramid 10 cm. Calculate the length of its side edges.
  7. Floating floor
    floor In the new building is considered a floating floor worker in each room. 30 minutes lay 9 m2 of the floor. How long 3 workers laid the floor in 4 rooms with a total area of 90 m2?
  8. Ski lessons
    skiing_2 On the ski course leaves 80 pupils. They live in triple and quadruple rooms. Count if rooms is the 23. How many are triple and quadruple rooms?
  9. Stairs
    schosy Between adjacent levels are 15 stairs. If step will be 1.2 cm lower there would be 16 stairs. What is the stair height?
  10. Bottles of juice
    juice_cones How many 2-liter bottles of juice need to buy if you want to transfer juice to 50 pitchers rotary cone shape with a diameter of 24 cm and base side length of 1.5 dm.
  11. Bank deposit
    bank_1 Ms Jana after the withdraw amount of 2,500 euros after year saving in bank. What was her deposit if the interest rate was 2.5% p.a..
  12. Cosine
    cosine The point (21, 20) is on the terminal side of angle θ. cos θ = ?
  13. Pair
    dvaja They have together 48 years - he has 2 times as she was when he was equal as she has today ....
  14. Tetrahedral prism
    hranol_1 The height of a regular tetrahedral prism is three times greater than the length of the base edge. Calculate the length of the base edge, if you know that the prism volume is 2187 cm3.
  15. Cars motion
    AB From point A car start at the speed of 90 km/h. Against it departs from the point B at the same time another car at 60 km/h. For how long and where they met if the distance between A and B is 180 km?
  16. Homework
    family Mother and Kate together weigh 27 kg more than the father. Father weighs 8.4 kg more than mother. Father weight 35 kg more than Kate. Determine weights of father mother and Kate.
  17. Shoes
    boty Peter decided to measure shoes size of his three friends. Measured accurately and wrote as follows: Venda and Jenda together 52 cm Jenda and Zdenda together 58 cm Zdenda and Venda together 54 cm a) How long measures Vendy, Jenda and Zdenda shoes together
  18. Pipe
    1pipes How long is the pipe with an outside diameter of 0.55 m if his coloring consumed 43 kg of color. 1 kg of color coverage is 10 m2.
  19. Lenka and money
    Karl_Lagerfeld_2014 When Lenka bought pants from 1/3 of her savings shirt from 1/5 and 1/8 spent at the hairdresser, she is left 328 Kč. How much money was saved? How much hairdresser cost?
  20. Three-digit numbers
    poker_hand_ranking How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?

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