According to a plan, a drilling team had to drill to a depth of $270$metres below the ground level. For the first three days, the team drilled as per the plan. However, subsequently finding that their resources were getting underutilised according to the plan, it started to drill $8$metres more than the plan every day. Therefore, a day before the planned date they had drilled to a depth of $280$metres. How many metres of drilling was the plan for each day?
 

Two pipes can fill a cistern in $14$and $16$hours respectively. The pipes are opened simultaneously and it is found that due to leakage in the bottom of the cistern, it takes $32$minutes extra for the cistern to be filled up. When the cistern is full, at what time will the leak empty it? 

A tank holds $100$gallons of water. Its inlet is $7$ inches in diameter and fills the tank at $5$ gallons/min. The outlet of the tank is twice the diameter of the inlet. How many minutes will it take to empty the tank if the inlet is shut off when the tank is full and the outlet is opened? (Hint: Rate of filling or emptying is directly proportional to the diameter) 

A tank of capacity $25$litres has an inlet and an outlet tap. If both are opened simultaneously, the tank is filled in $5$minutes. But if the outlet flow rate is doubled and taps opened the tank never gets filled up. Which of the following can be outlet flow rate in litres/min? 

X takes 4 days to complete one-third of a job, Y takes $3$ days to complete one-sixth of the same work and Z takes$5$ days to complete half the job. If all of them work together for $3$ days and X and Z quit, how long will it take for Y to complete the remaining work done?