The volume of the fish tank is 12 Litres.
How to find volume?
Volume of the fish tank is lengh×width×height
⇒50cm×12cm×20cm
⇒ 12000 cm³
How to convert cubic centimeters into litres?
1 cm³=1 ml
12000 cm³= 12000ml
1000 ml= 1 Litre
1 ml = 1/1000 Litres
∴ 12000 ml = (1/1000)×12000
⇒ 12 Litres
Learn more about volume here: http://brainly.brainly.com/question/1972490
#SPJ2
