List of top Mathematics Questions on Time, Speed and Distance asked in IIITH UGEE

A system consists of N particles, interacting with each other (for example, protein molecules). Which one of the following statements is FALSE?
Three pipes A, B, and C can fill a tank in 6 hrs. After working at it together for 2 hrs, C is closed and A and B can fill the remaining part in 7 hrs. The total number of hours taken by C alone to fill the tank is