Examples for 9th grade

  1. Hectoliters
    bazen_14 How deep is the pool if there are 2025 hectoliters of water and the bottom dimensions are a = 15 meters b = 7,5 meters and the water level is up to 9/10 (nine-tenths) of height.
  2. The pool
    inlet_1 The pool contains 220 m3 of water. The pool can be emptied either: a) 10 hours of pipe B and 8 hours of pipe A, or b) 10 hours of pipe A and 7 hours of pipe B. How many cubic meters of water will flow in 1 hour from pipe A and how many from pipe B?
  3. Three pumps
    pumps_5 We are filling the pool. The first pump would be filled in 12 hours, the second pump in 15 hours. If all three pumps were running at the same time, it would fill the pool for 4 hours. How long would the pool fill only with the third pump?
  4. Two cities
    cyclist_37 The distance between cities A and B is 132 km. At 9.00 am, the cyclist started the bike at an average speed of 24 km/h, and at 10.00 h started from the B cyclist at an average speed of 30 km/h. How long and far from A will they both meet?
  5. Three unknowns
    matrix_1 Solve the system of linear equations with three unknowns: A + B + C = 14 B - A - C = 4 2A - B + C = 0
  6. Cylinder height
    cylinder_9 Calculate the height of the cylinder and its surface is 2500 dm2 and the bases have a diameter 5dm.
  7. Square sides
    square_7 If the square side increases by 28%, the square circumference increases by 11.2 meters. Find the length of the original square side.
  8. Mixing water
    teplomer_17 The 30-liter container should we fill with water at 60 degrees Celsius. How many liters of water 80 degrees C hot and how many liters of water 20 degrees Celsius warm we have to mix?
  9. Helmet
    Clock0400_7 Nowadays cycling better results could be obtained not only due to rider physical preparation but also thanks to using updated technologies. One of the essential parts of the rider´s equipment is his or her helmet. While most bikers wear a helmet mainly t
  10. Working together
    workers_49 One worker performs work in 3 days, the second in 5 days. How much do they work together?
  11. Pooja
    clocks_14 Pooja and Deepa age is 4:5, 4 years back it was 8:11. What is the age of Pooja now?
  12. Bricks pyramid
    The_Great_Pyramid How many 50cm x 32cm x 30cm brick needed to built a 272m x 272m x 278m pyramid?
  13. Four poplars
    topolcany_1 Four poplars are growing along the way. The distances between them are 35 m, 14 m, and 91 m. At least how many poplars need to be dropped to create the same spacing between the trees? How many meters will it be?
  14. Find sales tax
    danky_1 What is 8.25% sales tax out of 1607.00?
  15. Express train
    trains_13 International express train drove from Kosice to Teplice. In the first 279 km, the track was repaired, and therefore it was moving at a speed of 10km/h less than it was scheduled to drive. The rest of the 465 km trip has increased the speed by 8 km/h than
  16. Combinations 7
    combinatorics A multi-course meal has 3 choices. 3 appetizers, 4 main courses, and 3 desserts. How many different combinations to choose from?
  17. Water reservoir
    nadrz_17 One drain hole emptied the water from the tank for 20 hours, with the second drain for 30 hours. How long will the water drain from this tank if we open two drains simultaneously?
  18. Beds
    stan_3 At the summer camp, there are 41 chalets. Some rooms are 3-beds, some 4-beds. How many campers from 140 are living in 3-bed?
  19. Selling price
    usd_11 Find the selling price. Cost to store: $50 Markup: 10%
  20. Honza
    calendar_6 Honza is 13 years old and Peter 21 years old. After how many years are their ages will be at ratio 7: 9?

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...