Answer:
![0.328\ l](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pht9lak7zlbpi1l1u7wcha0rgyq6puczsr.png)
Explanation:
Remember that
![1\ l=1,000\ cm^(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/yq9irc4ngyzaka3od7lk47v2jv3ml9x3sz.png)
step 1
Find the volume of the aquarium
The volume is equal to
![V=b^(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/p181lnr2vy5fb7v8k4b18lbapokbo3749o.png)
we have
![b=12\ cm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wky9is6x486ddrqtbbqnhksv74u8ma7s8f.png)
substitute
![V=(12)^(3)=1,728\ cm^(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/chhh47usj7x43piye9jcxjzw991fnhiv9v.png)
step 2
Convert to liters
![1,728\ cm^(3)=1,728/1,000=1.728\ l](https://img.qammunity.org/2020/formulas/mathematics/middle-school/j305rmnwjmov6kq2uu6f8lm076z3og1vxi.png)
step 3
Calculate how much more water is needed to fill the aquarium completely
Find the difference between the volume of the aquarium and the water that contains the aquarium
![1.728\ l-1.40\ l=0.328\ l](https://img.qammunity.org/2020/formulas/mathematics/middle-school/q5ihhm6u0hf6t631q4p538rb9ncrh64pe0.png)