Question

Câte numere de formă a 8 b c sunt divizibile cu 5

Answer 1

$\frac{}{a8bc} \: \: \: divizibil \: cu \: 5$
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.