Examples for 8th grade - page 75

  1. 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?
  2. MO 2016 Numerical axis
    osa Cat's school use a special numerical axis. The distance between the numbers 1 and 2 is 1 cm, the distance between the numbers 2 and 3 is 3 cm, between the numbers 3 and 4 is 5 cm and so on, the distance between the next pair of natural numbers is always in
  3. Aunt
    teta Annie aunt is 35 years old, Annie is 14 years. For how many years will aunt have twice as many years as Annie?
  4. Motel
    motorest Three different dinners A, B, C are served in the motel. Three 20 members went to motel. Group 1 ordered dinners: A 20 members and their average dinner price in the group was CZK 200. From Group 2, they ordered a A: 10 persons, B 10 dinners, and their aver
  5. Flowerbed
    garden_16 In the park there is a large circular flowerbed with a diameter of 12 m. Jakub circulated him ten times and the smaller Vojtoseven times. How many meters each went by and how many meters did Jakub run more than Vojta?
  6. Rhombus 4
    diamond_shape Circumference of the rhombus is 44 cm, its height is 89 mm long. Calculate its content area.
  7. Unknown number 24
    numbs_6 f we add 20, we get 50% of its triple. What is this unknown number?
  8. Simply equation
    img_reci Solve this equation for x: ?
  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. 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?
  11. Disc
    vysek.JPG Circumference of the disk is 78.5 cm. What is the circumference of the circular arc of 32° on the disc?
  12. 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?
  13. 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.
  14. 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?
  15. Equations
    p1110617 Solve following system of equations: 6(x+7)+4(y-5)=12 2(x+y)-3(-2x+4y)=-44
  16. 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.
  17. Percent
    percentage_2 Calculate how many % is the number 26.25 less than the number 105.
  18. Percentage - fractions
    rubik About what percentage we must increase number 1/6 to get number 1/3?
  19. Circle - simple
    colorful-circle Calculate the area of a circle in dm2, if its circumference is 31.4 cm.
  20. 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?

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.