Answer: 89.6 kg of water
Step-by-step explanation:
Find the total volume of the tank:
(80cm)*(35cm)*(40cm) = 112,000 cm^3
4/5 of this would be 89,600 cm^3
Water has a mass of 1 gram/cm^3
(1 gram/cm^3)*(89,600 cm^3) = 89,600 g of water
(89,600 g)*(1 kg/1,000 g) = 89.6 kg of water
