Răspuns:
5 la orice putere se termina in 5
5^1=5
5^2=25
5^3=125....
5^2020=....5
1*2*3*,,,2019=1*2*3*....*10*...*20*....30*...99*100....*2010*...2019=...0
Deci se termina in zero, deoarece avem cel putin pe 10 care introduce un 0
2*3=6
Deci suma se termina in 1
....5+...0+6=....1
