Bricks wall

There are 5000 bricks. How high wall thicknesses of 20 cm around the area, which has dimensions of 20 m and 15 m, can use these bricks to build? Brick dimensions are 30 cm, 20 cm, and 10 cm.

Correct answer:

w =  213.1 cm

Step-by-step explanation:

$$\begin{gathered} N=5000 \\ a=20\text{m} \\ b=15\text{m} \\ h=20\text{cm}\to \text{m}=20:100\text{m}=0.2\text{m} \\ V=N\cdot 0.30\cdot 0.20\cdot 0.10=5000\cdot 0.30\cdot 0.20\cdot 0.10=30{\text{m}}^3 \\ o=2\cdot (a+h+b)=2\cdot (20+0.2+15)=\frac{352}{5}=70.4\text{m} \\ S=h\cdot o=0.2\cdot 70.4=\frac{352}{25}=14.08{\text{m}}^2 \\ c=V/S=30/14.08=\frac{375}{176}\doteq 2.1307\text{m} \\ w=c\to \text{cm}=c\cdot 100\text{cm}=2.1307\cdot 100\text{cm}=213.1\text{cm}=213.1\text{cm} \end{gathered}$$

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