If the die is 6-sided, then for rolling a 3 on one the probability is 1/6.
On the second it is also 1/6.
Multiply them together to get probability for consecutively rolling a 3 on both.
1/6 x 1/6 = 1/36
As a decimal this is 0.028 (about 0.03) or 2.7
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%.
Hope this helps!