試題詳解

121. An urn contains four fair dice. Two have faces numbered 1, 2, 3, 4, 5, and 6； one has faces numbered 2, 2, 4, 4, 6, and 6； and one has all six faces numbered 6. One of the dice is randomly selected from the urn and rolled. The same die is rolled a second time.
Calculate the probability that a 6 is rolled both times.
(A) 0.174
(B) 0.250
(C) 0.292
(D) 0.380
(E) 0.417