Question

трехзначные числа из 9 и 1

Answer 1

111 = 100 + 10 + 1;
119 = 100 + 10 + 9;
191 = 100 + 90 + 1;
911 = 900 + 10 + 1;
199 = 100 + 90 + 9;
919 = 900 + 10 + 9;
991 = 900 + 90 + 1;
999 = 900 + 90 + 9.

Answer 2

111,119,199,191,911,919,999,991