यदि 12 कंपोज़िटर 5 घंटे में एक पुस्तक के 60 पृष्ठ कंपोज़ कर सकते हैं, तो 20 घंटे में उसी पुस्तक के 200 पृष्ठ कंपोज़ करने के लिए कितने कंपोज़िटरों की आवश्यकता होगी?

If P and Q together can complete a piece of work in 15 days and P alone can do it in 45 days, in how many days can Q alone complete that work?

A can lay a railway track between two stations in 16 days and B can do the same job in 12 days. With the help of C, they finished the job in 4 days. In how many days can C alone do the job?