a jeweler is using 10 pounds of alloy that is 2% platinum. He wishes to combine these mixtures to form a mixture that is 3% platinum. How many pounds of the second alloy should be added to the first to get a mixture that is 3% platinum

You can't solve this unless you have the amount of the other alloy.

Step-by-step explanation:

For example, the question should be something like:

A jeweler is using 10 pounds of alloy that is 2% platinum. He has another alloy that is 5% platinum. He wishes to combine these mixtures to form a mixture that is 3% platinum. How many pounds of the second alloy should be added to the first to get a mixture that is 3% platinum?

3 1/3 x 2 3/5 = 8 2/3

step-by-step explanation:

just multiply the first number by the second number to get your answer.