4. Replace the letters by (decimal) digits in the addition pattern below, so that the result of the addition is correct and different letters are replaced by different digits. There are two solutions, find them both. You may write a program to do so. SAVE + MORE MONEY 5. Let Son) denote the sum of digits in the base b representation of a natural number n. Does there exist a number n such that: a) S2(n) = S2(n + 1)? b) Sz(n) = S(n + 1)? c) Slo(n) = Slo(n + 2)