Toothpaste 81127

How long will the roll of toothpaste be extruded from the tube if the volume of the toothpaste is 100 ml and the diameter of the opening is 8 mm?

Correct answer:

x =  198.9 cm

Step-by-step explanation:

$$\begin{gathered} D=8\text{mm}\to \text{cm}=8:10\text{cm}=0.8\text{cm} \\ V=100\text{ml}\to {\text{cm}}^3=100\cdot 1{\text{cm}}^3=100{\text{cm}}^3 \\ r=D/2=0.8/2=\frac{2}{5}=0.4\text{cm} \\ V=\pi r^2\cdot x \\ x=\frac{V}{\pi \cdot r^2}=\frac{100}{3.1416\cdot 0.4^2}=198.9\text{cm} \end{gathered}$$

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