Find the probability of 4 turning up at least once in two tosses of a fair die.

Explanation

Let ` X `be the probability of getting `4` in two tosses of a fair die.
` X ` follows a binomial distribution with` n=2 ; p=frac{1}{6} and q=frac{5}{6};`


`P(X=r)=^{2} C_{r}(frac{1}{6})^{r}(frac{5}{6})^{2-r}`


Probability of getting ` 4` at least once` =P(X geq 1)`

`=1-P(X=0) `

`=1-^{2} C_{0}(frac{1}{6})^{0}(frac{5}{6})^{2-0} `

`=1-frac{25}{36} `

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