[tex] \frac{}{a8bc} \: \: \: divizibil \: cu \: 5 [/tex]
a € {1,2,3,4,5,6,7,8,9}
b € {0,1,2,3,4,5,6,7,8,9}
c € {0,5}
Exemple: 1800,1805,1810,1815,1820,1825,1830,1835,1840,1845,1850,1855,1860,1865,1870,1875,1880,1885,1890,1895.......
Nr. sunt 9•10•2=180 de nr.