If all three digits of a three-digit integer are the same, then if
that integer is divided by the sum of its digits, the quotient
always equals 37. Why?
If that digit is N, then
(1) the sum of its digits is N+N+N or 3N
and
(2) the integer itself is 100N + 10N + N = 111N = (3×37)N = (3N)×37
Edwin