An empty cistern has three pipes A, B and C. A and B can fill it in 24hrs and 30 hours respectively and C can empty it in 8hr 20 minutes. If these pipes are ope

An empty cistern has three pipes A, B and C. A and B can fill it in 24hrs and 30 hours

respectively and C can empty it in 8hr 20 minutes. If these pipes are opened in order at

1PM, 4PM and 6 PM, when will the cistern be empty again?​