Given, weight of the woman = 55 kg
For the first 10 kg, fluid required is 100 mL/kg
So for the first 10 kg volume of fluid required is 100 ml/kg x 10 kg = 1000 ml = 1 L
For the second 10 kg, fluid required is 50 mL/kg
So for the second 10 kg volume of fluid required is 50 ml/kg x 10 kg = 500 ml = 0.5 L
For the remaining (55 kg - 20 kg ) or 35 kg, fluid required is 20mL/kg
Now for the the remaining 35 kg volume of fluid required is 20 ml/kg x 35 kg = 700 ml = 0.7 L
The total volume of fluid per day required by a 55 kg woman = 1L + 0.5L + 0.7L = 2.2 L