SOLUTION: Hello. I'm having some difficulty figuring out the following word problem, Can you help me? A jeweler has 6 rings, each weighing 7 g, made of an alloy of 5% silver and 95% go

Algebra ->  Equations -> SOLUTION: Hello. I'm having some difficulty figuring out the following word problem, Can you help me? A jeweler has 6 rings, each weighing 7 g, made of an alloy of 5% silver and 95% go      Log On


   

Question 196218: Hello.
I'm having some difficulty figuring out the following word problem, Can you help me?
A jeweler has 6 rings, each weighing 7 g, made of an alloy of 5% silver and 95% gold. He decides to melt down the rings and add enough silver to reduce the gold content to 87%. How much silver should he add?
Thanks!
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the jeweler has 42g of alloy (6 times 7)

if the new alloy is 87% gold, then it is also 13% silver (87+13=100)

let x="amount of added silver"

the original amount of silver plus the added silver equals the new amount
___ (5%)(42) + x = (13%)(42+x)

2.1 + x = 5.46 + .13x

.87x = 3.36

x = 3.86 (approx)