contestada

A fair die is rolled repeatedly until a number larger than 4 is rolled. What's the probability that it takes you 4 rolls to roll a number greater than 4?
a) (1/3)³ * (2/3)
b) (1/3)⁴
c) (2/3)³ * (1/3)
d) (1/3)³ * (2/3)²