Question

Fie numerele:a=12345678910111213....979899 si b=4344454647...997998999.a)Cate cifre au numerele a si b? b)Cate zerouri contin numerele a si b?c) Cate cifre de 9 au numerele a si b?

Answer 1

a) Numarul a are (99 - 1) + 1 = 99 de cifre
    Numarul b are (99 - 43) + 1 = 57 de cifre
(regula : ultimul - primul + 1)

b) Numarul a are 9 cifre de 0 (1234...10...20.........90....9899)
    Numarul b are 5 cifre de 0 (4344...50...60...70...80...90...9899)

c) Numarul a are 9 + 11 = 20 cifre de 9 (...9...19.....89909192...99)
    Numarul b are 5 + 11 = 16 cifre de 9 (acelasi principiu)