# Six sided dice problem

· by tuxdna · Read in about 1 min · (40 words) ·

Six sided dice problem

Summary:

$$n = \sum_{k=1}^{\infty}{k*P(rolls=k)}$$

Where:

$$P(rolls=k) = q^{(k-1)} * p$$

p is probability we get a 6 in k’th roll, and q^(k-1) is probability we do not get a 6 in all k-1 rolls.