Examples for 8th grade - page 76

  1. Joshka
    money-false Joshka had € 15. Mama took him 15%. How many had left?
  2. Password dalibor
    lock Kamila wants to change the password daliborZ by a) two consonants exchanged between themselves, b) changes one little vowel to such same great vowel c) makes this two changes. How many opportunities have a choice?
  3. Donuts
    buchty_1 In the dining room at one table sit Thomas, Filip and Martin. Together they eat 36 donuts. How many donuts eaten everyone, when Filip ate twice as much as Thomas and Martin even half over Filip?
  4. Unknown number 24
    numbs_6 f we add 20, we get 50% of its triple. What is this unknown number?
  5. Buttons
    knofliky Shirt has 6 buttons, blouse has 4 buttons. All buttons are 176. Shirts and blouses are together 36. How many are the shirts and blouses?
  6. Cuboid - ratios
    kvader11 The sizes of the edges of the cuboid are in the ratio 2: 3: 5. The smallest wall have area 54 cm2. Calculate the surface area and volume of this cuboid.
  7. Combinations of sweaters
    sveter I have 4 sweaters two are white, 1 red and 1 green. How many ways can this done?
  8. Coins
    coins Denis and Zdeno together have 97 coins. If Denis had 4 coins less than he has now, the number of the coins would be in the ratio 14: 17. Determine the number of coins owned by Denis and Zdeno.
  9. Bath salts
    salt_1 Bath salt A weighs 900 grams and costs 36,40 CZK. Bath Salts B weighs 1000 grams, but costs 85 CZK. How much is a bath salt A cheaper than B one?
  10. Disc
    vysek.JPG Circumference of the disk is 78.5 cm. What is the circumference of the circular arc of 32° on the disc?
  11. Fuel economy
    car1_4 How many kilometers is sufficient petrol in the cylinder fuel tank with a diameter 40 cm and the base of tank length 1 m, when it is filled to 60% and if the car consume 15 liters per 100 km?
  12. Percent
    percentage_2 Calculate how many % is the number 26.25 less than the number 105.
  13. Pharmacy
    roztoky_3 The pharmacy add to 3 liters of 95-percent alcohol 5 liters of 38.04 percent alcohol. How many percent pharmacy got?
  14. Cube surface area
    cubes2_2 The surface of the cube was originally 216 centimeters square. The surface of the cube has shrunk from 216 to 54 centimeters sq. Calculate how much percent the edge of the cube has decreased.
  15. Percentage - fractions
    rubik About what percentage we must increase number 1/6 to get number 1/3?
  16. Circle - simple
    colorful-circle Calculate the area of a circle in dm2, if its circumference is 31.4 cm.
  17. Trio 2
    decide Decide whether trio of numbers is the side of a right triangle: 26,24,10.
  18. Cylinder surface area
    cylinder_2 Volume of a cylinder whose height is equal to the radius of the base is 678.5 dm3. Calculate its surface area.
  19. Blueberries 2
    boruvky_2 Lenka and Martin collected eight liters of blueberries in two hours. How long will take to collect blueberries by Lenka itself, if we know that she collect all 2.5 hours less than Martin?
  20. Common cylinder
    valec_2 I've quite common example of a rotary cylinder. Known: S1 = 1 m2, r = 0.1 m Calculate : v =? V =? You can verify the results?

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