day2_more_dice.py

"""
Task:
In a single toss of  fair (evenly-weighted) six-sided dice,
find the probability that the values rolled by each die
will be different and the two dice have a sum of .

Ans:
1/9
"""


from itertools import product
from sympy import symbols

# all dice values
roll = range(1, 7)

# list of boolean values, true if i+j <= 9
at_most_9 = [i!=j and i+j == 6 for i, j in product(roll, roll)]

# initiate var s and n
s, n = symbols("s n")

# prob as variable (result of s/n)
probability = s/n

# calculate sum of all true in at_most_9 as s
# len at_most_9 as n
ans = probability.subs(s, sum(at_most_9)).subs(n, len(at_most_9))

# print result
print(ans)