Equation - 9th grade (14y) - examples

  1. Rectangle
    rectangle_22 There is a rectangle with a length of 12 cm and a diagonal 8 cm longer than the width. Calculate the area of rectangle.
  2. Banknotes
    penize_49 Eva deposit 7800 USD in 50 banknotes in the bank. They had value 100 USD and 200 USD. How many were they?
  3. Average height
    meter_22 The average height of all pupils is 162 cm. The class teacher's height is 178 cm. The average height of all (teacher and all pupils) is 163 cm. Calculate the number of pupils in the class.
  4. The size
    trapezium_6 The size of a Trapezium are 3/4×cm, ×cm 2(×+1)cm and 3(×+2)cm long respectively if it's perimeter is 60cm, calculate the length of each side.
  5. 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?
  6. Peter and Paul
    clock-night-schr_16 Peter and Paul together have 26 years. Four years ago, Paul was twice older than Peter. How much is Paul and how much Peter?
  7. Tickets
    cinema2_16 1260 tickets sold. On the first day, 80% was sold on the second day was sold. How many tickets were sold first and how much the next day?
  8. Find the 7
    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
  9. Mushrooms
    hriby_1 Mushrooms lose 90% by weight drying. How many fresh mushrooms are needed for 5 kg of dried mushrooms?
  10. Simplify
    expr_3 Simplify expression - which expression is equivalent to: 3(m + 2) − 4(2m − 9)
  11. 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?
  12. Grandmother
    car_33 Mom walked out to visit her grandmother in a neighboring village 5km away and moved at a speed of 4km/h. An hour later, father drove down the same road at an average speed of 64km/h. 1) How long will take to catch mom die? 2) What is the approximate dis
  13. 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?
  14. Acid evaporation
    roztoky_12 How many kilograms of water do we have to evaporate from 100 kg of 32% acid to make it 80% concentration?
  15. Father and daughter
    time_14 When I was 11 my father was 35 year old. Now, father has three times older then me. How old is she?
  16. Granules
    dog_2 Katy had two dogs. The first one ate a pack of granules a week and the other two times longer. Katka bought them two bags of granules. How long does it last for both dogs?
  17. Journey 5
    tourists_12 A man has to do a journey of 84km in 3 hours. He travels the first 30km at 20km/hr. At what rate must he travel the remaining distance to complete his journey on time?
  18. Pupils
    skola_23 There are 350 girls in the school, and the other 30% of the total number of pupils are boys. How many pupils does the school have?
  19. Equation - inverse
    hyperbola_3 Solve for x: 7: x = 14: 1000
  20. Mushrooms
    huby_5 Grandfather gathered fresh mushrooms. The fifth was wormwood, and it was thrown away, the other dried up. He obtained 720 grams of dried mushrooms. How many kilograms did the grandfather collect, and by drying the mushrooms they lost 75% of their weight?

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.



Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?