Expression of a variable from the formula - math word problems

  1. Orchard
    tree_2 3/5 of the trees in the orchard are apples, 1/3 are cherries and the remaining five trees are pear. How many trees are in the orchard?
  2. Two machines
    machine_2 Performances of two machines are in a ratio of 7:12. A machine with less power produced 406 pieces of products per shift. a) How many pieces produced per shift second machine? b) How many pieces produced two machines together for five shifts?
  3. Square and rectangle
    ctverec Calculate the side of a square which content area equals area of the rectangle having a length of 3 cm greater and by 2 cm smaller than the side of the square.
  4. Bicycle gears
    rear_wheel_sprocket_cassette The toothed wheel on the bicycle pedal has 40 teeth, the wheel on the rear wheel has only 16 teeth. How many times does the rear wheel turn if the pedals rotate 50 times?
  5. Angle in RT
    triangles_10 Determine the size of the smallest internal angle of a right triangle whose sides constitutes sizes consecutive members of arithmetic progressions.
  6. Square s3
    squares_9 Calculate the diagonal of the square, where its area is 0.49 cm square. And also calculate its circumference.
  7. Diagonal of the rectangle
    rectangle_1 Calculate the diagonal of the rectangle which area is 54 centimeters square and the circuit is equal to 30 cm.
  8. Third member
    seq_6 Determine the third member of the AP if a4=93, d=7.5.
  9. Glass
    pohgar How many glass are needed to produce glass with base regular 5-gon if one base triangle in the base is 4.2 square cm and the height is 10 cm?
  10. Cuboid enlargement
    cubes_12 By how many percent increases the volume of cuboid if its every dimension increases by 30%?
  11. Cube edge
    cubes_9 Determine the edges of the cube when the surface is equal to 37.5 cm square.
  12. Cube 5
    cubes_10 The content area of one cube wall is 32 square centimeters. Determine the length of its edges, its surface and volume.
  13. Unknown number 7
    percents2_9 16% of the unknown number is by 21 less than unknown number itself. Determine the natural unknown number.
  14. Three children
    chocholate_1 3 children eat 8 chocolates in 6 days. How many chocolates 6 children eat in 18 days?
  15. Raspberries
    maliny_2 Dano had 20 raspberries. John had 90% more raspberries than Dano. Determine how many raspberries have Dano and Juraj together.
  16. Unknown number 5
    hyperbola_2 Daniel think an integer. When he change this number at a ratio of 2:5 he got number 2.8. Determine what number think Daniel.
  17. Rectangle
    rectangles_8 Perimeter of rectangle is 48 cm. Calculate its dimensions if they are in the ratio 5:3 (width:height)
  18. Coefficient
    gp Determine the coefficient of this sequence: 7.2; 2.4; 0.8
  19. Billiard balls
    balls_billiard A layer of ivory billiard balls of radius 6.35 cm is in the form of a square. The balls are arranged so that each ball is tangent to every one adjacent to it. In the spaces between sets of 4 adjacent balls other balls rest, equal in size to the original.
  20. Price saleoff
    2digits_1 Shoes standing y euros. At first they were discounted by 12% and then 50% of the new amount. After this double cheapening the cost was exactly 22 euros. Determine the original price of shoes.

Do you have an interesting mathematical word problem that you can't solve it? Submit math problem, and we can try to solve it.



We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...