Question

if we have a gold 40 gram of purity of 82 % and we have to make it of 90 % how much we need to add gold
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Answer 1

Answer:

3.90 g

Step-by-step explanation:

x of 82% = 40

or, x ×82/100 = 40

or, x = 40× 100/82

or x = 48.78

48.78 of 90% = 48.78×90/100 = 43.90

gold needed to add = (43.90- 40) = 3.90 g