Question

9^9 has how many digits,give reason.

Answer 1

Answer:

step by step explanation:

By multiplying a number with 9, you are making it a multiple of 9, and hence the sum of its digits must be divisible by 9. Since you can iterate the digit adding process until you get down to a single digit number, the result must be divisible by 9.

The only two single digit numbers divisible by 9 are 0 and 9, and you're never going to get 0 (well, unless your original number was 0 :)