Examples for 8th grade - page 61

  1. Mushrooms
    mushrooms-01 For five days, we have collected 410 mushrooms. Interestingly every day we have collected 10 mushrooms more than the preceding day. How many mushrooms we have collected during 4th day?
  2. Book
    books_1 Alena read a book at speed 15 pages per day. If she read twice as fast she should read a book four days earlier. How many pages have a book?
  3. Three dice
    3_cubes When you throw three dice was the sum total of the dice 10. The yellow dice fell one eye more than on the red and brown fell 3 eyes less than red. How many eyes fell on every dice?
  4. Regular triangular prism
    3b_hranol Calculate the surface area of body of regular triangular prism, when the length of its base edge is 6.5 cm and height 0.2 m.
  5. 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?
  6. Meat
    maso Half a kilogram of pork and three-quarters of a kilogram of beef cost total 6.6 USD. One quarter of a kilogram of beef and 1 kilogram of pork cost 6.3 USD. Determine the price of 1 kg of each type of meat.
  7. Fifth of the number
    numbs_5 The fifth of the number is by 24 less than that number. What is the number?
  8. Average speed
    earth_2 What is the average speed you have to move the way around the world in 80 days? (Path along the equator, round to km/h).
  9. Tmp workers
    profesiadays Three temporary workers cleaned 60 m of walkway in 5 hours. How many meters of the walkway cleared seven volunteers for eight hours?
  10. Coffee shop
    coffee-beans To the coffee shop brought 2 types of coffee totally 50 kg. The first type was CZK 220 per kilogram, coffee second type 300 CZK per 1 kg. For all the coffee trader earned CZK 12,000. How many kilograms of coffee of first type and how many kilograms of cof
  11. Saving
    2kc Paul save 155Kč in 46 2 Kc and 5Kc coins. How much saved 2Kc and 5Kc coins?
  12. Cube containers
    cubes_1 Two containers shaped of cube with edges of 0.7 m and 0.9 m replace a single cube so that it has the same volume as the original two together. What is the length of the edges of the new cube?
  13. Runners circle
    runners Pepa circles the track in 36 seconds. Kamil in 42 seconds. They started together. How many seconds will meet again at the start?
  14. Chord distance
    tetiva The circle k (S, 6 cm), calculate the chord distance from the center circle S when the length of the chord is t = 10 cm.
  15. Probability - tickets
    zreby What is the probability that when you have 25 tickets in 5000 that you wins the first (one) prize?
  16. Triangle midpoints
    sierpinski-geometry Determine coordinates of triangle ABC vertices if we know tirangle sides midpoints SAB [0;3] SBC [1;6] SAC [4;5], its sides AB, BC, AC.
  17. Surface area 2
    cubes Calculate how many % reduce the surface area of the cube is we reduced length of each edge by 10%.
  18. Loan
    money_2 If you take a bank loan $ 24000 and we want to repay after the year, we have to pay the total amount $ 24696/ What is the annual interest rate on this loan?
  19. Gearing
    prevod Gearing consists of two wheels, one is 88 and second 56 teeth. How many times turns smaller wheel to fit the same teeth as in the beginning? How many times will turn biggest wheel?
  20. Double percent
    percents What is 70% of 70% of 10500?

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