Question

Відсотковий зміст цинку у сплаві цинку та міді на 20% більше міді. Маса сплаву 200 кг. Скільки кг міді у цьому сплаві? Які можливі помилки можуть робити учні при розв’язуванні цієї задачі?

Answer 1

X+1.2x=200;
2.2x=200;
x=200/2.2;
x=90(90)

Answer 2

Percentage of Copper in Zinc-Copper Alloy

To find the amount of copper in the zinc-copper alloy, we need to determine the percentage of copper in the alloy and then calculate the mass of copper based on that percentage.

Given: - The percentage of zinc in the alloy is 20% more than the percentage of copper. - The total mass of the alloy is 200 kg.

Let's assume the percentage of copper in the alloy is x%. Since the percentage of zinc is 20% more than the percentage of copper, the percentage of zinc in the alloy would be (x + 20)%.

To find the mass of copper in the alloy, we can set up the following equation:

x + (x + 20) = 100

Simplifying the equation, we get:

2x + 20 = 100

Solving for x, we find:

2x = 80

x = 40

Therefore, the percentage of copper in the alloy is 40%.

To calculate the mass of copper in the alloy, we can use the following formula:

Mass of copper = (Percentage of copper / 100) * Total mass of alloy

Substituting the values, we get:

Mass of copper = (40 / 100) * 200 kg

Mass of copper = 80 kg

Therefore, there are 80 kg of copper in the zinc-copper alloy.

Possible Mistakes in Solving this Problem

When solving this problem, students may make the following mistakes:

1. Incorrectly calculating the percentage of copper: Students may incorrectly calculate the percentage of copper by not considering that the percentage of zinc is 20% more than the percentage of copper. It is important to carefully read and understand the given information before setting up the equation.

2. Misinterpreting the equation: Students may misinterpret the equation and set it up incorrectly. It is crucial to correctly set up the equation based on the given information and the problem statement.

3. Miscalculating the mass of copper: Students may make calculation errors when finding the mass of copper in the alloy. It is important to double-check the calculations to ensure accuracy.

By being aware of these possible mistakes, students can avoid them and solve the problem correctly.