Question

A metal alloy weighing 10mg and containing 85% gold is melted and mixed with 2mg of a different alloy which contains 55% gold. What percent of the resulting alloy is gold?

A) 70%
B) 75%
C) 80%
D) 85%

Answer 1

The percentage of gold in the resulting alloy is c. 80%.

Step-by-step explanation:

To find out the percentage of gold in the resulting alloy, we need to consider the amount of gold in each of the alloys and then calculate the total amount of gold in the resulting alloy.

First, let's calculate the amount of gold in the first alloy. The alloy weighs 10mg and contains 85% gold. So, the amount of gold in the first alloy is 10mg x 0.85 = 8.5mg.

Next, let's calculate the amount of gold in the second alloy. The second alloy weighs 2mg and contains 55% gold. So, the amount of gold in the second alloy is 2mg x 0.55 = 1.1mg.

Finally, let's calculate the total amount of gold in the resulting alloy. The total amount of gold is 8.5mg + 1.1mg = 9.6mg.

To find the percentage of gold in the resulting alloy, we divide the amount of gold in the resulting alloy by the total weight of the resulting alloy and multiply by 100. So, the percentage of gold in the resulting alloy is (9.6mg / 12mg) x 100 = 80%.