One kilogram of scrap metal is 2 1/2 kg of iron-rich ore. how much ore replaces 4 tons of scrap metal?

Let’s denote the unknown amount of iron ore, which replaces 4 tons of scrap metal, with the letter X.

Let us compare the proportion of 1 kg of scrap metal replacing 2.5 kg of iron ore and 4000 kg of scrap metal replacing an unknown amount of iron ore.

Let’s make a proportion and find X kg of iron ore:

1 kg of scrap metal – replaces 2.5 kg of ore;

4000 kg of scrap metal – will replace X kg of iron ore;

X = 4000 kg * 2.5 kg / 1 kg = 10000 kg = 10 tons.

Answer: 4 tons of scrap metal will replace 10 tons of iron ore.