Examples for 7th grade (seventh) - page 82

  1. Two thirds
    fractions_10 Find two-thirds of the number equal to two-thirds of 99
  2. Two gears
    gears-3 The two gears fit together. The larger gear has 32 teeth, the smaller has 20 teeth less. How many times does turn a smaller gear if the bigger gear turns three times?
  3. Game 27
    dice_4 Susan wanted to play the game. In the beginning, the first says a number from 1 to 8. Then the second player adds a number from 1 to 5 and tells the sum. Again, the Susan adds a number from 1-5 and say sum and etc. . . The winner must say the number 27. Wh
  4. Negative in equation
    eq1_7 2x + 3 + 7x = – 24, what is the value of x?
  5. Ophelia
    teplomer_9 Ophelia recorded the temperature of a cold store every two hours. 1. At 6am it was -4°C and at 8am it was -1°C. By how much did the temperature rise? 2. The temperature went up by 5°C in the next two hours. .What was the temperature at 10am?
  6. Half-sphere roof
    kupola_1 The roof above the castle tower has the shape of a 12.8 m diameter half-sphere. What is the cost of this roof, if the cost of 1 square meter is 12 euros and 40 cents?
  7. Fe metal sheet
    plech_1 For one product, 5/8 of the metal sheet are consumed, to the second 5/6 of remains. What part of the sheet metal is consumed for both products together?
  8. Area to volume
    two_cubes_2 If the surface area of a cube is 486, find its volume.
  9. A cylindrical tank
    tanks_8 A cylindrical tank can hold 44 cubic meters of water. If the radius of the tank is 3.5 meters, how high is the tank?
  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. Employees
    workers_45 Of all 360 employees, there are 11/12 women. How many men work in a company?
  12. Building
    wood_3 At the building, we divided 240 boards into two piles in a 5: 3 ratio. How many were fewer boards in the lower pile?
  13. Sum of four numbers
    seq_6 The sum of four consecutive natural numbers is 114. Find them.
  14. Barter
    kozky There is exchange trade on the market. We know that for two sheepskins we get three goat skins. We also know that for six rabbits skins we get four goat skins. How many rabbit's skins we get for four sheepskins?
  15. Solve 2
    numbers2_47 Solve integer equation: a +b+c =30 a, b, c = can be odd natural number from this set (1,3,5,7,9,11,13,15)
  16. Square prism
    prism_2 A square prism has a base with a length of 23 centimeters, what is the area in square centimeters of the base of the prism?
  17. Simple sequence
    sequence_geo_6 Continue with this series of numbers: 1792,448, 112, _, _
  18. To improve
    one_2 To improve her handwriting Paula practices writing the numbers 1 to 200 in words. How many times will she have written the word "one" in all?
  19. Temperature conversion
    teplomer_12 The normal human body temperature is 98.6 degrees Fahrenheit. What is the temperature in degrees Celcius?
  20. Bed time
    clock-night-schr_3 Tiffany was 5 years old; her week night bedtime grew by ¼ hour each year. If, at age 18, her curfew time is 11pm, what was her bed time when she was 5 years old?

Do you have an interesting mathematical word problem 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 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...