Pure gold is 24 carats,21 carat gold is 80% gold and the rest is other metals.18 carat gold is 75% gold and the rest is other metals. a) Work out the ratio of gold to other metals in: i) 18 carat gold ii) 21 carat gold iii) In a Jewelry ratio of gold to other metal is 4 : 1.If the gold used is 8g, then find the weight of other metals and hence find the total weight of the Jewelry..