Mathematics for IGCSE & O level - Ratio And Proportion (Section 5 - No. 30)
If 12 workers can complete a job in 20 days, how long will it take 15 workers to do the same job, assuming all workers work at the same rate?
15 days
16 days
18 days
25 days
説明
Inverse proportion: (12 workers * 20 days) / 15 workers = 16 days