An alloy of gold and silver containing 80% gold was fused with some silver, resulting in 20 kg

An alloy of gold and silver containing 80% gold was fused with some silver, resulting in 20 kg of a new alloy containing 70% silver. Determine how many grams of silver have been added.

1. The new alloy of gold and silver weighs: Mn = 20 kg;

2. It contains the amount of silver: Cn kg;

Cn = (70/100) * 20 = 14 kg;

3. Determine the amount of gold: Zn = 20 – 14 = 6 kg;

4. The original alloy contains gold: Z = 80% = 80/100 = 0.8;

5. The mass of gold is the same in both alloys;

6. Let’s calculate the mass of the initial alloy: M kg;

M = Zn / 0.8 = 6 / 0.8 = 7.5 kg;

7. The amount of added silver in the new alloy: Cd kg;

Cd = Mn – M = 20 – 7.5 = 12.5 kg.

Answer: 12.5 kilograms of silver were added to the new alloy.