An inspector needs an average defect rate under 5 across 6 inspected batches. The first five batches scored 4, 6, 3, 5, and 7. What is the highest score the sixth batch can have without the average reaching 5?

Correct answer to question 211 (Arithmetic Reasoning): 4

Method

The average must stay below 5, so the total across 6 batches must stay under 30. The first five batches sum to 25, leaving less than 5 for the sixth, meaning the highest whole score that keeps the average under 5 is 4.