Alloy of lead and tin weighing 50 kg. Contains 60% tin. How many kg of tin do you need to add

Alloy of lead and tin weighing 50 kg. Contains 60% tin. How many kg of tin do you need to add to the alloy to make it 75% tin?

Let’s find how much lead and tin are contained in 50 kilograms of the original alloy:
M ol = 50/100 * 60 = 30 kg – mass of tin;
M sv = 50 – 30 = 20 kg is the mass of lead.

Let’s calculate the percentage of lead in the new alloy:
100 – 75 = 25%.

If 20 kg of lead corresponds to 25% of the mass of the new alloy, then the mass of the entire alloy is:
20 * 100/25 = 80 kg.

Let us determine how much tin was added to the alloy by subtracting the mass of the initial one from the mass of the new alloy:
80 – 50 = 30 kg.

Answer: 30 kilograms of tin were added to the alloy.