Examples for 7th grade (seventh) - page 53

  1. Octagonal mat
    8gon_1 Octagonal mat formed from a square plate with a side of 40 cm so that every corner cut the isosceles triangle with leg 3.6 cm. What is the content area of one mat?
  2. Two rulers
    meters We have two rulers. Scale interval on first rulers are a spaced 1 cm and on second spaced 15 mm. Rulers are attached to each other so that they match initial divider commas. What next dividers commas coincide? Find at least three cases.
  3. Pulley
    kladka On wheels with a diameter of 40 cm is fixed rope with the load. Calculate how far is load lifted when the wheel turns 7 times?
  4. Concrete pipe
    beton-skruz How much will cost cover a 6 m long concrete pipe with an outer radius 1.5 m and inner radius 0.8 meters if 1 m2 paint costs 24 €.
  5. Internal angles
    angle_3 One internal angle of the triangle JAR is 25 degrees. The difference is the size of the two other is 15°. Identify the size of these angles.
  6. Store
    img-thing Peter paid in store 3 euros more than half the amount that was on arrival to the store. When he leave shop he left 10 euros. How many euros he had upon arrival to the store?
  7. Bridge piers
    bridge-369809_960_720 One quarter of the bridge pier is sunk into the ground. Two thirds are in the water. Protruding above the water is 1.20 m long. Determine the height of bridge piers.
  8. Ratios
    circle Divide: a) 250 CZK in the ratio 2:3 b) 1000 CZK in the ratio 4:7:9
  9. Chicks
    kuriatko How many chicks were hatched from 4500 eggs, when an average of 100 eggs hatched 87 chicks?
  10. Divisibility by 12
    numbers2 Replace the letters A and B by digits so that the resulting number x is divisible by twelve /find all options/. x = 2A3B How many are the overall solutions?
  11. Three digits number 2
    numbers_7 Find the number of all three-digit positive integers that can be put together from digits 1,2,3,4 and which are subject to the same time has the following conditions: on one positions is one of the numbers 1,3,4, on the place of hundreds 4 or 2.
  12. Bicycle wheel
    wheel_2 Bicycle wheel diameter is 62 cm. How many times turns the bicycle on the road 1 km long?
  13. Ornamental shrubs
    delnik_3 Children committed to plant 240 ornamental shrubs. Their commitment however exceeded by 48 shrubs. Write ratio of actually planted shrubs and commitment by lowest possible integers a/b.
  14. Trees
    stromy2 3/5 trees are apples, cherries are 1/3. 5 trees are pear. How many is the total number of trees?
  15. Pumps A and B
    pump_2 Pump A fill the tank for 12 minutes, pump B for 24 minutes. How long will take to fill the tank if he is only three minutes works A and then both pumps A and B?
  16. One-third
    krtek A one-third of unknown number is equal to five times as great as the difference of the same unknown number and number 28. Determine the unknown number.
  17. Sidewalk
    kruhovy-objazd The city park is a circular bed of flowers with a diameter of 8 meters, around it the whole length is 1 meter wide sidewalk . What is the sidewalk area?
  18. Expressions
    equation Expression (3a-7).(3a+7) is identical with: ?
  19. Cylinder twice
    valec_3 If the radius of the cylinder increases twice, and the height is reduced twice, then the volume of the cylinder increases (how many times?):
  20. Jam
    dzem Jar with jam weighs 800 grams. Jam weighs three times as much as the empty glass. What is the weight of jam that is in the glass?

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.