Twelve identical workers, working independently at a constant rate, can complete a fixed task in 15 days. How many workers are needed to complete it in 10 days? Enter the number of workers.

Explanation

The task contains 12 times 15, or 180 worker-days, so a 10-day schedule requires 180 divided by 10, which is 18 workers. Scaling the workforce down to 8 because the time was reduced would use direct proportion and leave too little labour for the fixed task.