Rectangular 6481

The bottom of the pool at the family house has a rectangular shape with dimensions of 5 m and 3.5 m. Its height is 1.2 m. How many kg of acrylic paint are needed to paint the bottom and walls of the pool if 1 kg of paint is enough for 6 m²? The coating is applied in 3 layers.

Correct answer:

m =  18.95 kg

Step-by-step explanation:

$$\begin{gathered} a=5\text{m} \\ b=3.5\text{m} \\ c=1.2\text{m} \\ h=1/6=\frac{1}{6}\doteq 0.1667{\text{kg/m}}^2 \\ o=2\cdot (a+b)=2\cdot (5+3.5)=17\text{m} \\ S=a\cdot b+c\cdot o=5\cdot 3.5+1.2\cdot 17=\frac{379}{10}=37.9{\text{m}}^2 \\ {m}_1=h\cdot S=0.1667\cdot 37.9=\frac{379}{60}\doteq 6.3167\text{kg} \\ m=3\cdot m_1=3\cdot 6.3167=18.95\text{kg} \end{gathered}$$

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