Examples for 8th grade - page 30

  1. Millionaire
    money_7 Mr. Smith have gone withdraw from bank saving interest € 1,500. How big was his initial deposit if the annual interest rate is 1.5%?
  2. Two looms
    stav On two different looms with different performance can be make required quantity of textile in 6 hours when both work together. On the first machine this quantity of the textile can make in 10 hours. How long should take make same quantity of textile on a s
  3. Probability - tickets
    zreby What is the probability that when you have 25 tickets in 5000 that you wins the first (one) prize?
  4. 3sides prism
    prism_3 The base of vertical prism is an isosceles triangle whose base is 10 cm and the arm is 13 cm long. Prism height is three times the height of base triangle. Calculate the surface area of the prism.
  5. 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.
  6. Tourists
    hiking From the cottage started first group of tourists at 10:00 AM at speed 4 km/h. The second started after them 39 minutes later at speed 6 km/h. How long and how many kilometers from the cottage will catch the first group?
  7. Hřiště
    playground Map scale is 1: 1000. The playground is rectangular and on the map has dimensions 10 cm and 5 cm What is area of playground in square meters in reality?
  8. Thales
    circles_1 Calculate the length of the Thales' circle described to right triangle with hypotenuse 44 cm.
  9. R Trapezium
    Trapezium_example Rectangular trapezium has bases 17 and 7 and area 80 cm2. What is its perimeter?
  10. Cuboid
    cuboid_1 The cuboid has a surface area 8710 cm2, the length of its edges are in the ratio 3:2:1. Calculate the volume of the cuboid.
  11. Work
    dlazba.pg First paver pave pavement for 33 hours. Second for 24 hours. Started first paver and after 5 hours, join the second. How long will they finish pavement?
  12. Barrel with liquid
    barrel Barrel with grain weight 263 kg. When it shed 43% of grain, ha weight 170 kg. What is the weight of empty barrel?
  13. Triangle angles
    triangles_2 The angles α, β, γ in triangle ABC are in the ratio 10:5:6. Calculate size of angles.
  14. Rectangle
    obdlznik_torta Area of rectangle is 1430. Its length is 29 larger than the width. What are the dimensions of the rectangle?
  15. Mother and daughter
    kresba_1 The ratio of years mother and daughter is 5:2. After 7 years the ratio is 2: 1. How many years ago daughter was born?
  16. Similarity
    podobnost ABC is a triangle wherein a = 4 cm, b = 6 cm, c = 8 cm. Is it similar to the triangle DEF: d = 3 cm, e = 4.5 cm, f = 6 cm? If so, determine the ratio of similarity.
  17. New computer
    pc_1 New computer process a certain amount of data for 6 hours. For how many hours will process the same amount of data older computer that has a quarter lower performance?
  18. Plum
    plumbs_1 On the platter are plum. How many were there if its have to be able to share equally among 8,10 and 12 children?
  19. Grandson and granddad
    vnuk_dedo Grandson with grandpa they counted how many years have together. Their product is 365. How many years is the sum of their years.
  20. Polygon 42
    12gon Which polygon has 42 more diagonals than sides?

Do you have interesting mathematical example 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 e-mail correctly and check whether you don't have a full mailbox.