Cube-shaped 32441

We painted a closed cube-shaped oil tank with an edge length of 1.5 meters twice with a protective coating. How many kilograms of paint did we use if 1 kg of paint is enough for 10 square meters?
How many liters of oil are in the tank if it is filled to the brim?

Correct answer:

m =  2.7 kg
V =  3375 l

Step-by-step explanation:

$$\begin{gathered} a=1.5\text{m} \\ n=2 \\ h=10{\text{m}}^2\text{/kg} \\ S=6\cdot a^2=6\cdot 1.5^2=\frac{27}{2}=13.5{\text{m}}^2 \\ n=2 \\ m=n\cdot S/h=2\cdot 13.5/10=2.7\text{kg} \end{gathered}$$

$$\begin{gathered} V_1=a^3=1.5^3=\frac{27}{8}=3.375{\text{m}}^3 \\ V=V_1\to \text{l}=V_1\cdot 1000\text{l}=3.375\cdot 1000\text{l}=3375\text{l}=3375\text{l} \end{gathered}$$

Try another example