AMC 10B 2025 (Problem 22)
A seven-digit positive integer is chosen at random. What is the probability that the number is divisible by , given that the sum of its digits is ?
If all the digits were , their sum would be .
Since the sum of the digits is ,
there are cases:
there are cases:
Favorable:
Case 1:
Case 2:
Two of should be and the third one should be .
Two of should be and the third one should be .
By Hints 5 and 6:
By Hints 3 and 7:
(A)