⟩ There are two sand clocks(timers) one complete totally in 7 minutes and other in 9-minutes we have to calculate with this timers and bang the bell after completion of 11- minutes!plz give me the solution.
1. Start both clocks
2. When 7 min clock complete, turn it so that it restarts.
3. When 9 min clock finish, turn 7 min clocks (It has 2 mints only).
4. When 7 min clock finishes, 11 min complete.
