Question

Задача: З 2.5 кг. соняшникового насіння виготовили 1.8 кг чистого насіння а) Скільки треба соняшника, щоб дістати 4.2 кг чистого насіння? b)Який відсоток маси насіння йде у відходи?

Answer 1

А)  Составим пропорцию:
                                       2,5 кг подсолнечника  - 1,8 кг чистого семени
                                                      х                    -  4,2 кг чистого семени 
х=(2,5*4,2):1,8=10,5:1,8=105:18=(5 и 15/18) кг =(5 и 5/6) кг подсолнечника

б)  Пропорция:     2,5 кг   -  100%
                               1,8 кг   -     у%
  у=(1,8*100):2,5=180:2,5=72%  чистого семени
Тогда отходов будет 100%-72%=28%

Answer 2

А)
2,5 кг - 1,8 кг
х кг    -  4,2 кг
х = 2,5*4,2/1,8 = 35/6 кг

b)
(2,5 - 1,8)/2,5*100 = 28%

Answer 3

Task Analysis

To solve this problem, we need to determine the amount of sunflower seeds required to produce 4.2 kg of clean seeds and calculate the percentage of seed mass that becomes waste.

Calculation

a) To find out how much sunflower seeds are needed to obtain 4.2 kg of clean seeds, we can use the given information that 2.5 kg of sunflower seeds produce 1.8 kg of clean seeds.

b) To calculate the percentage of seed mass that becomes waste, we can compare the difference between the initial amount of seeds and the amount of clean seeds obtained.

Solution

a) Amount of Sunflower Seeds Needed: - Using the given ratio, we can calculate the amount of sunflower seeds needed to obtain 4.2 kg of clean seeds. - Let's denote the amount of sunflower seeds needed as x kg. - We can set up a proportion to solve for x: - 2.5 kg is to 1.8 kg as x kg is to 4.2 kg. - Solving for x: - 2.5 / 1.8 = x / 4.2 - x = (2.5 / 1.8) * 4.2 - x ≈ 5.83 kg

b) Percentage of Seed Mass as Waste: - To find the percentage of seed mass that becomes waste, we can calculate the difference between the initial amount of seeds and the amount of clean seeds obtained. - The waste can be calculated as: - 2.5 kg - 1.8 kg = 0.7 kg - To find the percentage: - (0.7 kg / 2.5 kg) * 100% ≈ 28%

Conclusion

a) To obtain 4.2 kg of clean sunflower seeds, approximately 5.83 kg of sunflower seeds are needed. b) Approximately 28% of the sunflower seed mass becomes waste during the process.