1)
abc=ab+bc+ca
100a+10b+c=10a+b+10b+c+10c+a
100a+10b+c=11a+11b+11c
89xa=10c+b
89xa=cb(in baza 10, cu bara adica)
cb sunt cifre, rezulta 10<=cb<=99
Logic a=1, rezulta cb=89, c=8 si b=9
N=198
Verificare: 198=19+98+81, adevarat
2)
a=lungimea traseului
a=a/2 +(1/2)(a/2)+51
a=a/2 +a/4 +51 l x4
4a=2a+a+204
a=204Km