A pair of dice is thrown 4 times. If getting a doublet is considered a success, find the probability of two successes.

We know that the repeated tosses of a pair of dice are known as Bernouli trials.

Let the number of times of getting doublets in an experiment of throwing two dice simultaneously four times be x.

Thus, P(X = x) = ^{n}C_{x}q^{n-x}p^{x} , where x = 0, 1, 2, …n

= ^{4}C_{x} (5/6)^{4-x}(1/6)^{x}

= ^{4}C_{x} (5^{4-x}/6^{6})

Hence, Probability of getting 2 successes = P(X = 2)

= ^{4}C_{2}(5^{4-2}/6^{4})

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