Answer:
He should find 24 defective lightbulbs.
Explanation:
1. Divide the number of defective bulbs by the total number of bulbs for each section.
2. Make sure the number you get is the same each time.
3. Divide the guessed number of bulbs (24) by the total number of bulbs (336)
4. If the number you got for step 4 matches the number you got for step 3, then he is right