Final answer:
The factory experienced a 40% decrease in the production of airplane parts.
Step-by-step explanation:
To find the percent of decrease, we need to first calculate the difference in the number of airplane parts produced. The factory went from producing 5 parts a day to 3 parts a day, so the decrease is 5 - 3 = 2 parts.
Next, we divide the decrease by the original number of parts and multiply by 100 to get the percent. So, (2 / 5) * 100 = 40%.
Therefore, the factory experienced a 40% decrease in the production of airplane parts.