Answer:
P(A|B) = 1 / 6
Step-by-step explanation:
Assuming two fair sided dice with faces numbered 1 to 6.
By intuition, there can only be 6 possible outcomes, so probability is 1/6.
Illustration how to use conditional probability.
Given two events A, B, following is the equation of conditional probability
that A happens given B has already happened and observed.
P(A|B) = P( A intersect B ) / P(B)
In the given problem,
A = casting a double-six
B = casting a double
P(A) = (1 / 6) * (1 / 6) = 1/36
P(B) = (6/6) * (1/6) = 1/6
P(A|B) = 1/36 / (1/6) = 1/6