50 terms are bad enough, but this?!?!
The sequence:
Where each term, after the first, is more than times the previous term. For what value of will the term be a multiple of ?
The answer is 8.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
The n-th term can be written as Un = 10^(n-1) x + 777...7 (n-1) digit So U50 = 10^49 (x) + 77777....7. If the number can be divided by 9, the sum of the digit must be divisible by 9. The sum of the digit is 7 (49) + x. So x=8.