Examples for 8th grade - page 101

  1. Composite ratio
    penize_49 Jakub, Aneta, and Lenka divided 1342 USD in the ratio 5/2: 3/10: 1/4. How much did Lenka take?
  2. The farmer
    sheep_3 The farmer had 140 sheep. For the next year, she decided to change the number of sheep in ratio 10: 7. How many sheep will he have then?
  3. Test points
    test_2 If you earned 80% of the possible 40 points, how many points did you miss to get 100%?
  4. Profit per kilo
    jablone_10 The trader sells apples at a profit of 20% per kilogram. Today, he decided to reduce the price of apples by 10%. How much profit does the trader have today?
  5. Container
    cubes3_9 The container-shaped box with internal dimensions of 3.9 m, 3.25 m and 2.6 m was completely filled with goods in the same cubic boxes. How long edge could this box have?
  6. Find the 3
    segment_2 Find the distance and mid-point between A(1,2) and B(5,5).
  7. Fractions
    zlomky_13 Three-quarters of an unknown number are 4/5. What is 5/6 of this unknown number?
  8. Triplets
    age_2 Three years ago, the triplets Pavel, Petr, and Luke and their five-year-old sister Jane had together 25 years. How old is Jane today?
  9. Overtaking
    dopravni-znacka-zakaz-predjizdeni On the direct road, the passenger car overtakes the slower bus by starting to overtake 20 meters from the bus and after passing it ahead of it again 20 meters away. The car overtakes at a steady speed of 72 km/h, the bus goes at a steady speed of 54 km/h..
  10. Square
    stvorec Square JKLM has sides of length 24 cm. Point S is the center of LM. Calculate the area of the quadrant JKSM in cm2.
  11. Height as diameter of base
    valec_17 The rotary cylinder has a height equal to the base diameter and the surface of 471 cm2. Calculate the volume of a cylinder.
  12. Seawater
    ice_cubes Seawater has a density of 1025 kg/m3, ice 920 kg/m3. 8 liters of seawater froze and created a cube. Calculate the size of the cube edge.
  13. Sixty
    pigs_1 Sixty percent of one-fifteen of the total is equal to thirty. What are two percent of the total?
  14. Highway tunnel
    tunnel_1 The highway tunnel was built from two ends in the north-south direction. The average daily performance of the "northern party" rasters was higher than the average daily power of the "southern party" of the rasters. After 55 business days, both parties met.
  15. Irrigation sprinkler
    postrekovac_1 The irrigation sprinkler can twist with an angle of 320° and has a reach of 12 meters. Which area can irrigate?
  16. Circular arc
    obluk_1 Calculate the length of the circular arc if the diameter d = 20cm and the angle alpha = 142 °
  17. Two chords
    circle_chords There is a given circle k (center S, radius r). From point A which lies on circle k are starting two chords of length r. What angle does chords make? Draw and measure.
  18. Bricklayers
    murar Seven bricklayers will build the house in 630 days. How many bricklayers do we need to take after 150 days to complete the building for (additional) 336 days?
  19. Line segment
    lines_7 The 4 cm long line segment is enlarged in the ratio of 5/2. How many centimeters will measure the new line segment?
  20. Digit sum
    cisla_7 How many are three-digit numbers that have a digit sum of 6?

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