Answer:
960 cm.
Explanation:
For the first day:
Subtract the primary level of water by the 20% of it. 20% of 1500 is:
(Convert the percent to decimal)
Then subtract 1500 to 300. That would become 1200cm for the first day.
For the second day:
Subtract the level of water from the first day by 20% of it. 20% of 1200 is:
Then subtract 1200 to 240. That would become 960 for the second day.
The level of the water after 2 days is 960 cm.