tham khảo
https://olm.vn/hoi-dap/detail/49371559502.html
Co so so hang la:
(32002-30):2+1=15987
Tong S la:
(32002+30).15987:2=256047792
S=2[15+16+....+16001]
S=[15+16001+16+16001+.....+8008]
S=2.8008(2+2+.....+2+1)
S=2.14.572(2+2+....+2+1)
S=2.7.2.572(2+2+....+2+1)
⇒S⋮7