How much pure gold (24/24) is to be added to 15.0 grams of 14 k gold (14/24) to obtain 18 k gold (18/24)?

10 gram gold is added

Explanation:

given data

pure gold = (24/24)

added = 15 grams

gold = 14 K  ( 14/24)

gold = 18 K ( 18/24)

to find out

How much pure gold added

solution

we know here that when we add gold to get 20 K gold or 22K

so we added here 15 gram 14 K

we consider here m is pure gold added

so by composition here

we get

15 (14K)  + m ( 24 K) = ( 15 + m ) (18)    1

solve it and find m

m = 10

so 10 gram gold is added

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