18 carat gold contains

What do you mean by 18 carat gold ?

Percentage of gold in 18 carat gold is:

A jeweller has bars of 18 carat gold and 12 carat gold. How much of each must be melted together to obtain a bar of 16 carat gold, weighing 120g (Given pure gold is of 24 carat.)?

The mass of gold in an 18 carat gold ring of 4 g is :

Given that 24 carat gold is pure gold; n18 carat gold is (3)/(4) gold and 20 carat gold is (5)/(6) gold,the ratio of the pure gold in 18 carat gold to the pure gold in 20carat gold is 5:8 b.8:5 c.9:10 d.15:22

How will you convert 24 carat gold into 22 carat gold for making ornaments?