8+88+888+........=
8081(10n−1)−8n9
1081(10n−1)
8081(10n−1)+8n9
None of these
S=8+88+888+.....=89[9+99+999+......]89[(10−1)+(102−1)+(103−1)+.....]89[(10+102+103+......)−(1+1+1+......)]89[10.10n−110−1−n] =881[10n+1−9n−10] =8081(10n−1)−8n9
8 + 88 + 888 + .............n terms = ____