Ratio - 7th grade (12y) - math problems

On solving problems and tasks with proportionally, we recommend hint rule of three. Rule of three (proportionality) help solve examples of direct and inverse proportionality. Three members make possible to calculate the fourth - unknown member.

  1. The piglet
    piglet The weight of the piglet grew regularly by five kilograms for four months. Determine the proportion by weight of the piglet in each month, if the first weighed 35 kg.
  2. The dough
    cesto The dough contains water, flour, and sugar. Water and flour in a ratio of 2: 3, flour, and sugar in a ratio of 2: 1. Determine the ratio of all three components of the dough.
  3. Age of family
    age The age of father and son is in the ratio 10: 3. The age of the father and daughter is in ratio 5: 2. How old are a father and a son if the daughter is 20?
  4. Brass
    brass Brass is an alloy of copper and zinc in a ratio of 3: 2. How many grams does a component that required 270 g of copper weigh?
  5. Interior angles
    triangles_1 Calculate the interior angles of a triangle that are in the ratio 2: 3: 4.
  6. The angles ratio
    123_triangle The angles in the ABC triangle are in the ratio 1: 2: 3. find the sizes of the angles and determine what kind of a triangle it is.
  7. Lookout tower
    marhat Calculate the height of a lookout tower forming a shadow of 36 m if at the same time a column 2.5 m high has a shadow of 1.5 m.
  8. Garden exchange
    land The garden has the shape of a rectangular trapezoid, the bases of which have dimensions of 60 m and 30 m and a vertical arm of 40 m. The owner exchanged this garden for a parallelogram, the area of which is 7/9 of the area of a trapezoidal garden. What is
  9. Ducats
    dukat The king divided the ducats to his three sons in a ratio of 2: 5: 4. How many ducats the king divided them if the youngest received 260 ducats, which was the least of all sons.
  10. Marlon
    meter Marlon drew a scale drawing of a summer camp. In real life, the sand volleyball court is 8 meters wide. It is 4 centimeters wide in the drawing. What is the drawing's scale factor? Simplify your answer and write it as a ratio, using a colon.
  11. Profitable company
    penize Three businessman decide to open up their own company. They agree to distribute the yearly profits made in the same ratio as their initial investments. They invest R 50 000, R 75 000 and R25 000, respectively. The profit made by the company in the first y
  12. The bakery
    cake The bakery baked 325 cakes from 25kg flour. How many kg of flour do they need to bake 195 pieces of such cakes?
  13. Altitude difference
    promile What a climb in per mille of the hill long 4 km and the altitude difference is 6 meters?
  14. Father and daughter
    family Father is 36 years old, daughter is 20 years less. What will be the ratio between them when they are 10 years more?
  15. Ages
    calendar Father is 36 years old, his daughter is 4 years old. Write down the ratio of the age of father and daughter. In what ratio will the ages of father and daughter after 4 years?
  16. Age ratio
    calendar Janko is 14 years old. The age ratio of Janka and Zuzka is 2: 3. What was the ratio seven years ago?
  17. Rate 3
    time_1 A liquid is heated at a rate of 5 degrees Celsius per minute. If the temperature now is at 39 degrees Celsius, after how long will the temperature be 94 degrees Celsius?
  18. Pizza
    pizza Three siblings ordered one pizza. Miška ate a quarter of the whole pizza. Lenka ate a third of the rest and Patrik ate half of what Lenka had left. They had the rest packed up. How much of the pizza did they pack? Write the result as a fraction.
  19. Two trains
    trains Two trains departed from City A and City B against each other. They met after some time. The first train then took 9 hours to reach city B, and the second train took 4 hours to reach city A. In what proportion were the train speeds?
  20. Two villages
    mapa On the map with a scale of 1:40000 are drawn two villages actually 16 km away. What is their distance on the map?

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