Calcula la cantidad de estaño contenida en 200g de bronce si su riqueza es de 18%.

The amount present is 36g

Explanation:

Here, we are interested in calculating the amount of zinc in the bronze alloy since it is 18% of the total mass

What we do here is to calculate 18% of the total 200g

Mathematically, that would be 18/100 * 200 = 18 * 2 = 36g