Question

find the sum to n terms of the series 7+77+777...

Answer 1

iything after the after increase like 7+77+777+7777..........

Answer 2

You will have to use Sampling , it is a process to find the pattern:

7(1+11+111+11111+.....)

For First 1 it is 7*1

For Second it is  1+11=12 , 7*12

For Third it is 1+11+111=123 , 7*123

So it goes on ...

All  you have to do is Multiply 7 By N

Where N = 1 if there are 1 Number and 12 if there are 2 Numbers And 123 if there are 3 Numbers