###Human: A tank can hold 100 liters of water. At the beginning of the rainy season, the tank is 2/5 filled with water. On the first day of the rainy season, the tank collected 15 liters of water. On the second day, 5 liters more water was collected than on the first day. On the third day, the tank was already filled. How many liters of water were collected on the third day?, ### Assistant: At the beginning of the rainy season, the tank is filled with 100 x 2/5 = 40 liters of water.
On the first day of the rainy season, the tank had 40 + 15 = 55 liters of water.
On the second day, 15 + 5 = 20 liters of water were collected.
So, the tank is filled with 55 + 20 = 75 liters of water on the second day.
Therefore, 100 - 75 = 25 liters of water were collected on the third day. 
 So the answer is :  25