Question

Сколько кг золота добавили к 0,4 кг серебра, если получили сплав с содержанием 20 % золота? Помоги те пожалуйста,срочно!!!​

Answer 1

Ответ:

2 кг золота

Пошаговое объяснение:

100*0,4=40

40:20=2кг золота не за что

Answer 2

Calculating the Amount of Gold Added to Silver to Obtain a 20% Gold Alloy

To calculate the amount of gold added to 0.4 kg of silver to obtain a 20% gold alloy, we can use the following formula:

Amount of Gold = Total Alloy Weight * Percentage of Gold - Amount of Silver

In this case, the total alloy weight is the sum of the gold and silver, which is the amount of gold added plus the initial amount of silver.

Calculation

Using the given information: - Initial amount of silver = 0.4 kg - Percentage of gold in the alloy = 20%

We can calculate the amount of gold added to the silver using the formula mentioned above.

Amount of Gold = (0.4 + x) * 20% - 0.4

Where x is the amount of gold added.

Solution

Solving for x: 0.2 = (0.4 + x) * 0.2 - 0.4

0.2 = 0.08 + 0.2x - 0.4

0.2 - 0.08 + 0.4 = 0.2x

0.52 = 0.2x

x = 0.52 / 0.2

x = 2.6 kg

So, 2.6 kg of gold needs to be added to 0.4 kg of silver to obtain a 20% gold alloy.