Q24:A United States presidential coin

2018 Test B Math · Question 24 of 57

A United States presidential coin is made from an alloy of four metals—copper, zinc, manganese, and nickel—with weights in the ratio of , respectively. The coin weighs a total of 8 grams. What is the weight of the zinc in this coin?

  • A0.28 g
  • B0.48 g
  • C0.96 g
  • D48 g
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Correct answer: B

Add the four values in the ratio

(177 + 12 + 7 + 4 = 200)

and use the sum as the denominator. Use that to find the fraction of zinc in one of the coins. Then reduce the fraction:

Multiply this fraction by 8 to find the number of grams of zinc in decimal form:

8 x 0.06 = 0.48