Find the sum of the digits of the number 6+66+666+6666 + ... +666...66, where the last number contains 100 digits.

Sum of the digits of the number

Step-by-step explanation:

Step(i):-

Given series

6+66+666+6666 + ... +666...66 up to 100 digits

Taking common '6'

6 ( 1 + 11 +111+ 1111+1111+.................11111....11 100 digits)

Multiply '9' and divisible by'9'

Multiply inside '9'

Step(ii):-

we know that sum of geometric series

we know that

a + a + a+........n terms = n a

 ....(i)

The sum of the 100 digits in geometric series

Now the equation (i)

The sum of the digits of the number  

Final answer :-

Sum of the digits of the number

312312

step-by-step explanation:

d is the answer

step-by-step explanation: