Final answer:
Bracelet C has the highest portion of gold with 64%. Bracelet A has 58%, and Bracelet B's percentage is unclear due to what appears to be a typographical error. The provided example calculation shows that an 18K green color gold jewelry piece contains 75% gold.
Step-by-step explanation:
The question requires us to identify which bracelet contains the highest portion of gold. To answer this question, we need to compare the gold content in each bracelet by interpreting the provided numbers as percentages. Bracelet A has 58%, which is clear. Bracelet B's value is 1320, which does not seem to be in a percentage format and likely contains a typo or an error. Bracelet C has 0.64, which can be interpreted as 64% when converting the decimal to a percentage. Therefore, Bracelet C has the highest portion of gold with 64% gold content.
To calculate the percentage of gold in a piece of jewelry, such as the provided example of an 18K green color gold jewelry piece with 7.5 g of gold, 2.0 g of silver, and 0.5 g of copper, we combine the weights to get the total weight and then divide the weight of the gold by the total weight:
Total weight = 7.5 g gold + 2.0 g silver + 0.5 g copper = 10.0 g
Gold percentage = (7.5 g gold / 10.0 g total) * 100% = 75%
In this example, the 18K gold jewelry piece contains 75% gold.