The digits from 1 to 6 are arranged to form a six-digit multiple of 5. What is the probability that the number is greater than 550,000? Express your answer as a common fraction.

When the first is 5 and the 2nd digit is 6, you have: 1 x 1 x 4 x 3 x 2 x 1==24 such numbers.

When the first digit is 6, then you have: 1 x 5 x 4 x 3 x 2 x 1 ==120 such numbers.

24 + 120 ==144 integers > 550,000

Sorry, I missed " express as fraction"

144 / 6! ==144 / 720 ==1 / 5