Insulating 25471

The septic tank is 6 m high and 2.4 m in diameter. If the painter consumes 1 kg per 5 m² and the paint is delivered in two kg cans, how many packages of insulating paint must he order?

Correct answer:

n =  6

Step-by-step explanation:

$$\begin{gathered} h=6\text{m} \\ D=2.4\text{m} \\ r=D/2=2.4/2=\frac{6}{5}=1\frac{1}{5}=1.2\text{m} \\ {S}_1=\pi \cdot r^2=3.1416\cdot 1.2^2\doteq 4.5239{\text{m}}^2 \\ {S}_2=2\pi \cdot r\cdot h=2\cdot 3.1416\cdot 1.2\cdot 6\doteq 45.2389{\text{m}}^2 \\ S=2\cdot S_1+S_2=2\cdot 4.5239+45.2389\doteq 54.2867{\text{m}}^2 \\ p=2\cdot 5=10{\text{m}}^2 \\ n=\lceil S/p\rceil =\lceil 54.2867/10\rceil =6 \end{gathered}$$

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