The alloy contains 28% copper, 56% iron, and the rest is nickel. How many kg of nickel are in 1200kg of alloy?

It is known from the condition that the alloy contains 28% copper, 56% iron, and the rest is nickel. In order to find how many kg of nickel in 1200 kg of alloy, we will compose and solve the proportion.

But first of all, let’s find out what percentage of nickel the alloy contains. Let’s take the alloy as 100% weight, then

100% – (28% + 56%) = 100% – 84% = 16%.

Let’s write down the proportion.

1200 kg – 100%;

x kg – 16%.

1200 / x = 100/16;

We are looking for an unknown middle term of the proportion:

x = (1200 * 16) / 100 = 19200/100 = 192 kg of nickel is contained in 1200 kg of alloy.