player mirror the placement. prove AFB So ist player always has a space - contrapositive to place until Ind player cannot put a com. to AS I Prove 7 B3 7 A 14 prove by contradiction . It is not possible. contradiction assum It can't be done . assum Aand =13 a b 10atb = 100 plate. and get a 1 2 90 ath where a = sum of digits in 1oth contradiction. b =. in 1 place. J 4 3loath = 100 atb = 45 a = 9 , contradiction. : a should be an integer.14. Is it possible to write numbers using all 10 digits 0, 1, ...,9 exactly once such that their sum is equal to 100? 14.* Generalize for different bases