Answer:
21 liters of water
Step-by-step explanation:
Let's say if you consume 2 liters of water when you run the tap and brush at the same time.
Also when you don't run the tap while you brush, you only use 0.5ilters
Now assuming you brush at least twice a day, this alone shows that you will use 0.5x2= 1L
Instead of 2x2= 4l.
Hence, in one day you will save 4-1= 3L
Therefore for a week you will save
3x7= 21 liters of water
