Question

We have two silver bullion, one law 0.750 and one law 0.950. What weight should be taken from each ingot to obtain 1800 g 0.900 sterling silver?

A) 450g from .750 and 1350g from .950
B) 290g from.750 and 1926g from .950
C) 1450g from .750 and 689g from .950
D) None of the answers are correct

Answer 1

Option A

Explanation:

To balance the silver at the exactly correct concentration, the first step is to focus only on the silver content in each bullion. This means that we can multiply the total weight of each piece by its concentration, to find the exact amount of silver inside. So, for instance, the target is 1800g of 0.9 sterling silver, and 0.9*1800=1620 g of silver. Now we can test A, B, and C to see if they contain that amount. In A, 450*0.75+1350*0.95=1620, which is a match! I tested the other two options, and neither of them had the correct amount of silver. Therefore, the answer is option A. Hope this helps!