Question

While mining, Nancy found a Large metal bar that contain 12 g of copper. Nancy also determined that the bar was 80% copper. What was the total weight of the metal bar in grams?

Answer 1

15 grams

Explanation:

If the copper made up 80% of the weight of the bar (w), then the bar weighed ...

0.80w = 12 g

w = (12 g)/0.80 = 15 g

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Copper has a density of about 8.96 g/cm³, so Nancy's "large" metal bar is about the size of two sugar cubes.