In fact, of the 15 people
6 work at a slower rate
9 work at a faster rate.
What does this mean about the number of hours it will take to complete the job? Tick one box.

In part (a), we calculated the time based on the assumption that all 15 people worked at the same, average rate. The result was 6 hours. Now, this assumption is changed. We have a mixed group: - 6 people work at a "slower rate". - 9 people work at a "faster rate". The key issue is that we don't know the magnitude of these different rates. - The "slower rate" could be just 1% slower or it could be 90% slower. - The "faster rate" could be just 1% faster or it could be 200% faster. Because more people (9) are working faster than are working slower (6), it might seem that the job will be completed more quickly. However, if the 6 "slow" workers are extremely slow, their negative impact on the total work output could outweigh the positive impact of the 9 "fast" workers, even if the fast workers are only slightly faster than average. Without knowing the specific rates of work for each group, we cannot compare the new average rate to the original average rate. Therefore, **it is not possible to say** how the completion time will be affected.