Probability Question based on two die. Divide the product by a multiple of three

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A die is rolled four times. What is the probability that exactly two multiples of 3 are rolled?

I know that the multiples of 3 in the dice are only 3 and 6. Therefore there would be a for getting three or six would be :

$\frac{2}{6}$$=$$\frac{1}{3}$

Then since there are two die we would have to multiple them together so we get: $\frac{1}{3}$$*$$\frac{1}{3}$$=$$\frac{1}{9}$

This is the part that I don't understand. Would I have to multiply four like this : $4$$*$$\frac{1}{9}$ to get $\frac{4}{9}$ or would I have to do something else.

Help would be appreciated.

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Let probability of event A be P(A) & probability of event B be P(B)

Provided that event A is independent of event B,
The probability of BOTH A & B Happening = P(A AND B) = P(A) * P(B)

We write it as P(A $\cap$ B) = P(A) $\times$ P(B)

Hope this helps