1+2+3+4+5+6+7+8+9+10 + 9 + 9+9+9+9+9+9+9+9+9+9+9 = 154 nho k nha
1+2+3+4+5+6+7+8+9+10+9+9+9+9+9+9+9+9+9+9+9+9
= 55 + 9 x 12
= 55 + 108
= 163
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9
= ( 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 10 ) + ( 9 x 12)
= 55 + 108
= 163