Question

An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 90 grams of an alloy containing 15% copper with 70 grams of an alloy containing

35% copper.
Answer the questions below. Do not do any rounding.
(a) How many grams of copper are in the resulting mixture?
grams
(b) What percentage of the resulting mixture is copper?

Answer 1

A) 38 grams of copper

B) 23.75% copper

Explanation:

(a) To find how many grams of copper are in the resulting mixture, we can calculate the amount of copper in each of the two alloy components and then add them together.

For the first alloy:

• Copper content = 15% of 90 grams = 0.15 * 90 grams = 13.5 grams

For the second alloy:

• Copper content = 35% of 70 grams = 0.35 * 70 grams = 24.5 grams

Now, add the copper content from both alloys:

• 13.5 grams (from the first alloy) + 24.5 grams (from the second alloy) = 38 grams

So, there are 38 grams of copper in the resulting mixture.

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(b) To find the percentage of copper in the resulting mixture, we can use the formula:

➟ Percentage of copper = (Copper content in mixture / Total weight of mixture) * 100

We already calculated the copper content in the mixture as 38 grams.

Now, let's find the total weight of the mixture:

• Total weight of mixture = 90 grams (from the first alloy) + 70 grams (from the second alloy) = 160 grams

Now, plug these values into the formula:

• Percentage of copper = (38 grams / 160 grams) * 100 = 23.75%

So, the resulting mixture contains 23.75% copper.