SOLUTION: A coin consists of 1/5 zinc, 1/10 manganese, and 1/40 copper. The rest of the coin is nickel. What fraction of the coin is nickel?

Question 414585: A coin consists of 1/5 zinc, 1/10 manganese, and 1/40 copper. The rest of the coin is nickel. What fraction of the coin is nickel?
Found 2 solutions by gwendolyn, Gogonati:
Answer by gwendolyn(128) (Show Source): You can put this solution on YOUR website!
Let n= the amount of nickel in the coin.

This means that the coin's consistency (represented by the '1,' because all of the materials in the coin should add up to make a whole coin) is equal to all of the materials added together, including the unknown amount of nickel.
To solve this, we should first add together the like terms (all the fractions).

Therefore, we know that:

Finally, to determine the value of n, we should subtract the total amount of non-nickel material from the whole of the coin to determine how much nickel is in it.

Therefore, of the coin is nickel.
Answer by Gogonati(855) (Show Source): You can put this solution on YOUR website!
1-(1/5+1/10+1/40)=1-13/40=27/40
27/40 of a coin is nickel.
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