A die is rolled 20 times and the number of twos that come up is tallied. Find the probability of getting exactly four twos.

Question

kropot72 · Answer

The probability of getting any particular number on one roll of a die is 1/6.
The outcome of each roll of the die is independent of the other outcomes. The binomial distribution can be used to find the probability of getting exactly four twos.
Do you know the binomial distribution?

anonymous · Answer

Probability = numberoftimesrolledCnumberoftwos . (probabilityofgettingatwo)^numberoftwos . (probability of not getting a two)^number of NOT twos
= 20C4 . (1/6)^4 . (5/6)^16