Probability

2000004703

Level: 
A
There is a wooden cube with faces painted in green. Its edge is \(3\,\mathrm{cm}\) long. Imagine, we cut the cube into small unit cubes with the edge length of \(1\,\mathrm{cm}\) and we select one of the unit cubes at random (see the picture). What is the probability of selecting a unit cube with three faces painted in green?
\( \frac{8}{27} \)
\( \frac{7}{27} \)
\( \frac{4}{27} \)
\( \frac{6}{27} = \frac{2}{9}\)

2000004704

Level: 
A
There is a wooden cube with faces painted in green. Its edge is \(3\,\mathrm{cm}\) long. Imagine we cut the cube into small unit cubes with the edge length of \(1\,\mathrm{cm}\) and we select one of the unit cubes at random (see the picture). What is the probability of selecting an unpainted cube?
\( \frac{1}{27}\)
\( \frac{3}{27} = \frac{1}{9}\)
\( 0\)
\( \frac{1}{6}\)

2000004705

Level: 
A
A distracted secretary prepares three envelopes and types three different letters for three different people. Then she randomly places the letters in the prepared envelopes. What is the probability of at least two recipients receiving the right letter?
\( \frac{1}{6} \)
\( \frac{1}{3} \)
\( \frac{2}{3} \)
\( \frac{3}{6} = \frac{1}{2}\)