11+22+33+44+55+66+77+88+99+111 = 606
Đáp số : 606
k mk nha
11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99 + 111
= (11 + 99) + (22+88) + (33+77) + (44+66) + 55 + 111
= 110 * 4 + 55 + 111
= 440 + 55 + 111
= 606
duyệt nhanh
11+22+33+44+55+66+77+88+99+111
= [11+99]+[22+88]+[33+77]+[44+66]+[55+111]
= 110+110+110+110+166
=440+166
=606