SOLUTION: A jeweler has 5 rings, each weighing 18 grams, made of an alloy of 18% silver and 90% gold. She decides to melt down the rings and added enough silver to reduce the gold content to
Algebra.Com
Question 993621: A jeweler has 5 rings, each weighing 18 grams, made of an alloy of 18% silver and 90% gold. She decides to melt down the rings and added enough silver to reduce the gold content to 75%. How much silver should she add?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A jeweler has 5 rings, each weighing 18 grams, made of an alloy of 18% silver and 90% gold. She decides to melt down the rings and added enough silver to reduce the gold content to 75%. How much silver should she add?
-------
Weight of rings:: 90 grams
If the result is 75% gold, it must be 25% silver.
----
Equation:
silver + silver = silver
18%(weight) silver + 100%(weight) silver = 25%(weight) silver
-----------------------------------------
0.18*90 + 1*x = 0.25(90+x)
Multiply thru by 100 to get::
---
18*90 + 100x = 25*90 + 25x
Solve for "x", which is the amt. of 100% silver you add
----
100x-25x = 25*90-18*90
------
75x = 7*90
x = (19/15)*7
x = 8.8667 grams (amt. of 100% silver to add)
--------
Cheers,
Stan H.
----
RELATED QUESTIONS
A jeweler has five rings, each weighing 18 grams made of an alloy of 10% silver and 90%... (answered by ankor@dixie-net.com)
A jeweler has 6 rings, each weighing 18 g, made of an alloy of 7% silver and 93% gold.... (answered by josgarithmetic)
A jeweler has 3 rings, each weighing 18 g, made of an alloy of 7% silver and 93% gold.... (answered by josmiceli)
A jeweler has five rings, each weighing 18 g, made of an alloy of 10% silver adn 90%... (answered by Paul)
A jeweler has five rings, each weighing 18g, made of an alloy of 10 percent silver and 90 (answered by richwmiller)
Mixture Problem: A jeweler has five rings, each weighing 18g, made of an alloy of 10%... (answered by ankor@dixie-net.com)
A jeweler has 5 rings, each weighing 12 g, made of an alloy of 5% silver and 95% gold.... (answered by Theo)
A jeweler has 2 rings, each weighing 24 g, made of an alloy of 5% silver and 95% gold.... (answered by stanbon)
A jeweler has 5 rings, each weighing 16 g, made of an alloy of 15% silver and 85% gold.... (answered by stanbon)