To answer this question, let us start by making a representation of the situation
We are asked to calculate in how much time the tank will be filled, note that 3 liters of water are falling into the tank every second so we have the next sequence of states
* After one second, there are 3 liters in the tank;
*After two seconds, there are 6 liters in the tank;
* After 3 seconds, there are 9 liters on the tank
And so on, so to find how many seconds it will take to fill the tank we must find haw many times i can put 3 liters of water in the tank, that is, we have to calculate:
![How\text{ many times I can put 3 liters in the tank= }(54)/(3)=18=\text{ It takes 18 seconds }](https://img.qammunity.org/2023/formulas/mathematics/college/qm3srj4brbgbb2dxgych16ycvlfk346p1c.png)
We conclude that to fill a tank with capacity 54 liters putting water at rate of 3 liters per second it will take 18 seconds.