# SIMPLE PROBABILITY Q

• November 1st 2008, 10:28 AM
abey_27
SIMPLE PROBABILITY Q
The sides of a fair six-sided dice are numbered from 1 to 6
The dice is thrown three times
Find the probabilitty that it shows a 1 at least twice.
• November 1st 2008, 11:35 AM
janvdl
Quote:

Originally Posted by abey_27
The sides of a fair six-sided dice are numbered from 1 to 6
The dice is thrown three times
Find the probabilitty that it shows a 1 at least twice.

This is a binomial distribution.

$P(X \geq 2) = \sum_{n = 2}^{3} {3 \choose n} \left( \frac{1}{6} \right) ^{n} \left( \frac{1}{6} \right) ^{3 - n}$