Final answer:
To determine the new price of an earphone after a 60% markup, calculate the markup amount by multiplying $129.50 by 0.60 to get $77.70, and add it to the original price, resulting in a new price of $207.20.
Step-by-step explanation:
If the cost of an earphone is $129.50 and it would have a 60% markup, the new price can be found by calculating the markup amount and adding it to the original price. To calculate the markup, you multiply the original cost by the percentage of the markup:
Markup = Original Cost × Markup Percentage
Markup = $129.50 × 0.60
Markup = $77.70
After calculating the markup, we add it to the original cost to find the new price:
New Price = Original Cost + Markup
New Price = $129.50 + $77.70
New Price = $207.20
Therefore, the new price of the earphone after a 60% markup will be $207.20.