In an alloy of gold and silver, the mass of gold relates to the mass of silver as 2: 5.

In an alloy of gold and silver, the mass of gold relates to the mass of silver as 2: 5. 1) What is the mass of gold in an alloy containing 80 g of silver? 2) What is the mass of silver in an alloy containing 18 g of gold?

Let the mass of one part be x grams.

Then the mass of gold in the alloy is:

2 * x = 2x grams.

And the mass of silver in the alloy is:

5 * x = 5x grams.

1) If the alloy contains 80 grams of silver, then:

5x = 80,

x = 16 grams,

2x = 2 * 16 = 32 grams of gold.

Answer: The mass of gold in this alloy is 32 grams.

2) If the alloy contains 18 grams of gold, then:

2x = 18,

x = 9 grams,

5x = 5 * 9 = 45 grams of silver.

Answer: The mass of silver in this alloy is 45 grams.