18. 19. 20. Which of the following integrals converge? (2 marks] m :r'fEl + l a. . dz 1 14236 no '5 z + 1 b. [1 31+ '5 d1: c. f I + {2 1 IE d. f I 3' as 1 .7: e. None of the above A tank contains 1000 litres of pure water. Brine that contains 0105 kg of salt per litre of water enters the tank at a rate of 5 litres per minute. Brine that contains 004 kg of salt per litre of water enters the tank at a rate of 10 litres per minute. The wellmixed solution drains from the tank at a rate of 15 litres per minute. Apprmhnately how much salt is in the tank after one hour? [2 marks] a] 0.34 kg b} 6.4 kg c} 16.9 kg d) 25.7 kg e) None of the above. A tank contains 1000 litres of pure water. Brine that contains 005 kg of salt per litre of water enters the tank at a rate of 5 litres per minute. Brine that contains 004 kg of salt per litre of water enters the tank at a rate of 10 litres per minute. The wellmixed solution drains from the tank at a rate of 15 litres per minute. Approximately how much salt is in the tank if the brine is allowed enter the tank continuously? a. 6.4 kg b. 16.9 kg c. 25.7 kg cl. The tank will contain an innite arnonnt of salt. e. None of the above