114) If Biochemical oxygen demand (BOD) of a town is 20000 kg/day and BOD per capita per day is 0.05 kg, then population equivalent of town is

115) The rate of BOD exerted at any time is

116) The ratio of 5 day BOD to ultimate BOD is about

117) In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C.The BOD of raw sewage will be

118) The minimum dissolved oxygen which should always be present in water in order to save the aquatic life is