Adding Concentration Problem
Problem: Joe has a ring weighing 10 grams made of an alloy of 13% silver and the rest gold. He decides to melt down the rings and add enough silver to reduce the gold content to 69%. How many grams of silver should he add?
My set up is:
10 (.13 + .87) = 10 (.13 + X + .69)
I'm not sure if that's correct.
Re: Adding Concentration Problem
Quote:
Originally Posted by
ayyisei 
Problem: Joe has a ring weighing 10 grams made of an alloy of 13% silver and the rest gold. He decides to melt down the rings and add enough silver to reduce the gold content to 69%. How many grams of silver should he add?
My set up is:
10 (.13 + .87) = 10 (.13 + X + .69)
I'm not sure if that's correct.
Let the amount of silver (in gram) added be X.
Then 10 + X = 10(0.87) + (10+X)(0.31).
