Question 2
For each of the numbers $1,19,199,1999,\ldots$, one card is made and labeled with that number. (a) Can at least three cards be selected so their sum has all digits equal to 2 except one? (b) If some cards have such a sum, what can its digit different from 2 be? Original weights: (a) 2 points, (b) 3 points.
