from itertools import permutations
from fractions import Fraction
valid, divisible, first_one = 0, 0, 0
for digits in permutations(range(6), 4):
    if digits[0] == 0:
        continue
    valid += 1
    number = 1000 * digits[0] + 100 * digits[1] + 10 * digits[2] + digits[3]
    if number % 5 == 0:
        divisible += 1
        first_one += digits[0] == 1
assert first_one == 24
result = {"total": valid, "divisible": divisible,
          "p_divisible": str(Fraction(divisible, valid)),
          "p_first_one_given_divisible": str(Fraction(first_one, divisible))}
import json
print(json.dumps(result, ensure_ascii=False, sort_keys=True))