ऋचा ने अपनी यात्रा 16:45 पर शुरू की और 23:10 पर समाप्त की। यात्रा पूरी करने में उसके द्वारा लिया गया समय कितना है?

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?