a)Cele doua pagini de la mijloc sunt numerotate cu doua numere naturale consecutive.
x+x+1=135
2x=134
x=134/2=67
In concluzie cartea are 67+67=134 pagini.
b)1,2,...,9=9 cifre
10,11,..,99=90x2=180 cifre
100,101,...,134=35x3=105 cifre
Total cifre=9+180+105=294
c)Paginile
ce contin cifra 2
sunt;2,12,20,21,22,23,24,25,26,27,28,29,32,42,52,62,72,82,92,102,112,120,121,122,123,124,125,126,127,128,129,132.Cifra
2 a fost folosita de 34 ori.
