Find sum to n terms of sequence 8, 88, 888, 88888,..
Let Sn = 8 + 88 + ...... + n terms
Sn = 8{1 + 11 +......... + n terms}
Xly by 9 on both side
∴ 95/n8 = 9 + 99 + 999 +.... + to n term
