Dissolved oxygen values of four water samples A, B, C and D are respectively 1 ppm, 3ppm, 5 ppm and 7 ppm. Which is more polluted ?

Dissolved oxygen values of four water samples A, B, C and D are respectively 6 ppm, 5 ppm, 1 ppm and 3 ppm. Which is more polluted?

Dissolved oxygen values of four water samples A, B, C and D are respectively 6 ppm, 5ppm, 1ppm and 3ppm. Which is polluted ?

Biochemical oxygen demand values off our water samples A, B, C and D are respectively 50 ppm, 100 ppm, 150 ppm and 40 ppm. Arrange them in the descending order of their purity.

Biochemical oxygen demand values of four water samples P, Q, R and S are respectively 100 ppm, 50 ppm, 150 ppm and 10 ppm. Arrange them in the descending order of their purity.

Biochemical oxygen demand value of four water samples P, Q, R and S are respectively 100 ppm, 50 ppm,150 ppm and 10 ppm. Arrange them in the descending order of their purity

B.O.D values of four samples of water A,B,C and D are given below A 160 ppm B 35 ppm C 180 ppm D 25 ppm