Just divide 100% by 80% and multiply that answer by 5. I'm pretty sure that's how you do it.
9514 1404 393
Answer:
8
Step-by-step explanation:
The number of days has gone down by a factor of 15/24. The number of workers is inversely proportional, so must increase by a factor of 24/15 = 8/5.
(5 workers) × (8/5) = 8 workers
8 workers are needed to complete the project in 15 days.