CIMA Exam CIMAPRA19-P03-1 Topic 5 Question 28 Discussion

CH makes a popular type of chocolate bar The bars are made on a production line and are scanned for size and shape as they move along the line Wrong sized and misshapen bars are rejected as being poor quality. The scanner detects 90% of poor quality bars. If CH wants to reduce the risk of poor quality bars being sold to the public it can add a further check by a person scanning the production line as well. this check would detect 80% of poor quality bars

If the further check was implemented what percentage of poor quality bars would still get through the checking process?