A penny has a total mass of 3.1 grams. Zinc makes up 2.9 g of the penny. What is the percentage of zinc in the penny?

Find the proportion, and multiply it by 100 to get the percentage.

The proportion is 2.9/3.1=0.935

The percentage is 0.935*100=93.5

Answer: 93.54%

Explanation: Divide the mass of the zinc by the total mass of the penny.

2.9/3.1=0.9354

To get to a percent, multiply by 100.

0.9354 x 100 = 93.54

The mass of the zinc in the penny is 93.54%.