1/28. The probability that both songs are rock songs is 1/28.
The easiest way to solve this problem is using probability.
This is a example of probability without replacement, using the probability property of P(A∩B) = P(A)*P(B).
The probability of choose a rock song is P(A) = 2/8, and the probability to choose the second song from the 7 songs remaining and be rock song assuming that the first song that she picked was rock song is P(B) = 1/7.
The probability that both songs are rock song is:
P(A∩B) = P(A)*P(B)
P(A∩B) = (2/8)(1/7) = 2/56
P(A∩B) = 1/28