Final answer:
The fraction is 3/500 and the percentage is 0.6%.
Step-by-step explanation:
To write the ratio of defective gears to total gears produced, we can write it as the fraction 3/500. This means that for every 500 gears produced, there are 3 defective ones.
To write this as a percentage, we can use the formula:
Percentage = (Part/Whole) * 100
In this case, the part is 3 defective gears and the whole is 500 gears produced. Plugging these values into the formula, we get:
Percentage = (3/500) * 100 = 0.6%
Therefore, the fraction is 3/500 and the percentage is 0.6%.