The ingot contains 45% copper and equal amounts of five other metals

The ingot contains 45% copper and equal amounts of five other metals, one of them magnesium. How much magnesium is contained in the ingot?

Let’s determine the total mass of metals that are contained in the ingot, with the exception of copper:

Ingot weight – 100%.

The mass of copper is 45%.

This means that the mass of the remaining metals will be:

100 – 45 = 55% – the mass of the remaining metals in the ingot.

The remaining five metals are said to be in equal amounts. So we can determine the mass of magnesium:

55: 5 = 11% – the mass of magnesium in an ingot.

Answer: The mass of magnesium in the ingot is 11%.