Answer:
a. 0.78%
Step-by-step explanation:
Given data:
Total percentage of hydrosphere = 2.5%
Percentage of ground water = 31%
Percentage of hydrosphere we use for drinking = ?
Solution:
Percentage of hydrosphere we use for drinking = Percentage of ground water /100 × Total percentage of hydrosphere
By putting values,
Percentage of hydrosphere we use for drinking = 31 / 100× 2.5
Percentage of hydrosphere we use for drinking = 0.78%