Answer: 64%
Step-by-step explanation:
Given : A coin contains 9 grams of nickel and 16 grams of copper for a total weight of 25 grams .
i.e. Total weight of coin = 25 grams
weight of copper in a coin = 16 grams
Then , the percentages the metal in coins is copper is given by :-
[tex]\dfrac{\text{Copper in a coin}}{\text{Total weight of a coin}}\times100\\\\=\dfrac{16}{25}\times100\\\\=64\%[/tex]
Hence, the percentages the metal in coins is copper = 64%
