Conveting 18ct to 22ct gold?

Question

i have 350.84gm of 69.5%touch gold , now i want to convert it to 75% touch so how much i add pure to get 75% touch gold

Answer 1

If I understand correctly that you have 350.85 grams of .695 fine gold,

that you want to convert to 18K (.750 fine)

Then there is  350.85 x  .695 = 243.84075 grams of 24K gold in it.

So we set up an equation. g will be the amount of gold that we will add.

(243.84075 + g ) / (350.85 + g ) = .750

The new amount of the pure gold divided by the new total weight must be .750

So fiddling the numbers,

( 243.84075 + g ) = 0.750 x ( 350.85 + g )

243.84075 + g = 263.1375 + .75g

0.25g = 19.29675

g = 77.187 grams

Check:

(243.84075 + 77.187  ) / (350.85 + 77.187  )

321.02775 / 428.037 = 0.75

Grandpa

Answer 2

77.1848 g 100% gold

Be sure to show your work.

Answer 3

huh?  if you can smelt it you can remove impurities.

Answer 4

What is this you have. Is it a peice of jewelery ask a jeweler who specialises in making jewelery. It's obviously not a gold nugget because that is pure gold and the reason they don't make jewelery out of pure gold is that it is to soft so they add a harder metal. 18 ct is more than 75% pure gold so I don't quite understand what you want