|
Question 836591: The purity of gold is measured in karats, with pure gold being 24 karats. Other purities of gold are expressed as proportional parts of pure gold. How much pure gold should be mixed with 12-karat gold to obtain 72 grams of 18-karat gold?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! The purity of gold is measured in karats, with pure gold being 24 karats.
Other purities of gold are expressed as proportional parts of pure gold.
How much pure gold should be mixed with 12-karat gold to obtain 72 grams of 18-karat gold?
:
18k is halfway between 12k and 24k, therefore it would be half and half
:
But if you want use a mixture equation:
:
If 24 karats is pure gold, then
18 karats = 18/24 = .75
12 karats = 12/25 = .50
:
let g = amt of pure gold
then
(72-g) = amt of 12 karat gold
:
The mixture equation
.50(72-g) + g = .75(72)
36 - .5g + g = 54
-.5g + g = 54 - 36
.5g = 18
g = 18/.5
g = 36 grams of pure gold
and
72 - 36 = 36 grams of 12 karat gold
|
|
|
| |
