A full tube contains $75 \mathrm{ml}$ of toothpaste. How many meters of toothpaste could be squeezed out of it, if we know that the diameter of the cross-section of the squeezed toothpaste is $6 \mathrm{~mm}$?
A kinyomott fogkrém a $6 \mathrm{~mm}$ átmérőjú $h$ meter long cylinder will be. The volume of the toothpaste in the tube is equal to the volume of this cylinder.

$$
75 \mathrm{ml}=75 \mathrm{~cm}^{3}=0.3^{2} \cdot \pi \cdot h
$$

from which

$$
h=\frac{75}{0.09 \cdot \pi} \mathrm{cm} \approx 2.653 \mathrm{~m}
$$

Varga Áron (Alexandria, Monroe High School, USA, 10th grade)