12. Six weights look the same, with masses of 101 grams, 102 grams, 103 grams, 104 grams, 105 grams, and 106 grams. Place these six weights on a balance, three on each side, and the result is that the right side of the balance is heavier. The probability that the 106-gram weight is on the right side of the balance is $\qquad$ $\%$.
$80$