[" 0.X "[" X "^(" Q7.")" A cullindrical drum,of the top,contains "30],[" is litres of water.It drain at the top,contains "30" is "30" il "],[" opening at the bottom."10" lites out throught comes is "30" il "],[" out in the bottom."10" lites of water comes "],[," out in the "t_(1)" ,the next "10" lites of water comes "],[,t_(2)" and the last "10" lites in a further time "],[,t_(2)" and the last "10" lites in a further time to "],[" or Rough Work "]]