Expression of a variable from the formula - math word problems

  1. Completing square
    eq2_5 Solve the quadratic equation: m2=4m+20 using completing the square method
  2. Balloon and bridge
    hlbkovy_angle From the balloon, which is 92 m above the bridge, one end of the bridge is seen at a depth angle of 37° and the second end at depth angle 30° 30 '. Calculate the length of the bridge.
  3. The painter
    painter_12 In order for the painter to get the desired color, he must mix green and yellow in a ratio of 4: 7. If it has 28 l of green color, how many liters of yellow color should he add? How many liters of mixed color does he get?
  4. Greg and Bill
    Clock0400_12 Greg is 18 years old. He is 6 less than 4 times Bill's age. How old is Bill?
  5. Cube surface and volume
    cube_diagonals_5 The surface of the cube is 500 cm2, how much cm3 will be its volume?
  6. Unknown mixed number
    zlomky_23 Find the number that is smaller than 5 5/12 by as much as 2 2/13 is smaller than 6 1/6
  7. The observatory
    kupola The dome of the hemisphere-shaped observatory is 5.4 meters high. How many square meters of sheet metal needs to be covered to cover it, and 15 percent must be added to the minimum amount due to joints and waste?
  8. Calculate 3
    cube_sphere_in_1 Calculate the cube volume whose edge is 3x-1,3x-1,3x-1
  9. Simplify
    expr_3 Simplify expression - which expression is equivalent to: 3(m + 2) − 4(2m − 9)
  10. Isosceles triangle
    iso_tr_1 In an isosceles triangle, the length of the arm and the length of the base are in ration 3 to 5. What is the length of the arm?
  11. Which
    plusminus_11 Which decimals when subtracted equal 3.89: a - b = 3.89
  12. Rectangular plot
    rectangular plot The dimensions of a rectangular plot are (x+1)m and (2x-y)m. If the sum of x and y is 3m and the perimeter of the plot is 36m. Find the area of the diagonal of the plot.
  13. Rectangular triangle
    rt_triangle_2 The lengths of the rectangular triangle sides with a longer leg 12 cm form an arithmetic sequence. What is the area of the triangle?
  14. Rectangular field
    rectangle_inside_circle_2 A rectangular field has a diagonal of length 169m. If the length and width are in the ratio 12:5. Find the dimensions of the field, the perimeter of the field and the area of the field.
  15. Children playground
    lich_5 The playground has the shape of a trapezoid, the parallel sides have a length of 36 m and 21 m, the remaining two sides are 14 m long and 16 m long. Determine the size of the inner trapezoid angles.
  16. Sum of four numbers
    seq_6 The sum of four consecutive natural numbers is 114. Find them.
  17. Area to perimeter
    circle11_3 Calculate circle circumference if its area is 254.34cm2
  18. Sales off
    sale_6 The price has decreased by 20%. How many percents do I have to raise the new price to be the same as before the cut?
  19. Bottle
    cylinder_11 A company wants to produce a bottle whose capacity is 1.25 liters. Find the dimensions of a cylinder that will be required to produce this 1.25litres if the hight of the cylinder must be 5 times the radius.
  20. Two cyclists 2
    cyclist_45 At the same time, two cyclists left the towns A and B at constant speeds. The first one going from town A to town B, and the second one from town B to town A. At one point of the trip they met. After they met, the first cyclist arrived at town B in 36min,

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...