A goldsmith has two gold alloys. The first alloy is 30% gold; the second alloy is 80% gold. How many grams of each should be mixed to produce 50 grams of an alloy that is 68% gold?

Question

A goldsmith has two gold alloys. The first alloy is 30% gold; the second alloy is 80% gold. How many grams of each should be mixed to produce 50 grams of an alloy that is 68% gold? 
amount of 30% gold ______grams
amount of 80% gold ______grams

Reiny · Answer

let x be the amount of 30% gold then 50-x is the amount of 80% gold solve for x: .3x + .8(50-x) = .68(50)

Anonymous · Answer

a chemist has two alloys one of which is 5% gold and 15% lead and the other of which is 25% gold and 30% lead how many grams of each of the two alloys should be used to make an alloy that contains 40g of gold and 93g of lead ?