Grade - examples - page 81

  1. Quiz
    quiz Tested student answered correctly on a 4/ 8 questions. Wrong answers was 16. How many questions answered?
  2. Miraculous tree
    tree Miraculous tree grows so fast that the first day increases its height by half the total height of the second day by the third, the third day by a quarter, etc. How many times will increase its height after 6 days?
  3. Sum of series
    question Determine the 6-th member and the sum of a geometric series: 5-4/1+16/5-64/25+256/125-1024/625+....
  4. Apples
    apples_5 A 2 kg of apples cost a certain sum of money. This sum is equal to the amount of kilograms for which we pay 72 CZK. How much is 1 kg of apples?
  5. Disjoint
    sets How many elements have union and intersection of two disjoint sets when the first have 1 and secodn 8 elements.
  6. RT and circles
    r_triangle Solve right triangle if the radius of inscribed circle is r=9 and radius of circumscribed circle is R=23.
  7. Lunch
    lunch Jane eats whole lunch for the 30 minutes. Which part of the lunch is eaten in 180 seconds?
  8. Height of the arc - formula
    sircular_segment Calculate the height of the arc if the length of the arc is 77 and chord length 40. Does exist a formula to solve this?
  9. The book
    book The book has 280 pages. Each side is a rectangle with sides 15 cm and 22 cm. a) how many leaves has the book? b) at least how many square meters of paper should be used to production this book?
  10. Beer permille
    pivo In the 5 kg of blood of adult human after three 10° beers consumed shortly after another is 6.6 g of the alcohol. How much is it as per mille?
  11. Wheels
    tractor Small tractor wheel with a diameter of 60 cm must be rotated 8 times to overcome some pathway. How many times must turn the big tractor wheel with a radius 60 cm to overcome the same distance?
  12. Salary increase
    vyplata Ms. Merry salary increased by 15% and that was 83e. What should pay before the increase?
  13. Five tractors
    tractor_1 Five tractors plow field in 4.8 hours. How long plow this field if after 1.5 hours of work two tractors went to a different field?
  14. Barrel 2
    barell Empty barrel weighs 7 kg. When it filled with water up to 45% height, weighs 60 kg. How heavy is barrel full of water?
  15. Hexagonal pyramid
    jehlan_6 Regular hexagonal pyramid has dimensions: length edge of the base a = 1.8 dm and the height of the pyramid = 2.4 dm. Calculate the surface area and volume of a pyramid.
  16. Rectangle Anton
    anton_rec Difference between length and width of the rectangle is 8. Length is 3-times larger than the width. Calculate the dimensions of the rectangle.
  17. Annie
    dukatove_buchticky Annie had a few cents in wallet. She bought a 3 buns for 9 cents. Now she has 58 cents in the wallet. How many cents previously Annie had in the wallet?
  18. Brackets
    brackets Place one pair of brackets in expression 20-16 + 10 - 4 - 2 so that the result will be 0.
  19. Pyramid in cube
    pyramid_in_cube In a cube with edge 12 dm long we have inscribed pyramid with the apex at the center of the upper wall of the cube. Calculate the volume and surface area of the pyramid.
  20. Parcel
    land_parcel Both dimensions of the rectangular parcel were increased by 26%. By how many % has increased its acreage?

Do you have an 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.