MathDB
Problems
Contests
National and Regional Contests
Russia Contests
All-Russian Olympiad
1962 All-Soviet Union Olympiad
9
9
Part of
1962 All-Soviet Union Olympiad
Problems
(1)
Number with 1998 digits.
Source: 1962 All-Soviet Union Olympiad
1/15/2018
Given is a number with
1998
1998
1998
digits which is divisible by
9
9
9
. Let
x
x
x
be the sum of its digits, let
y
y
y
be the sum of the digits of
x
x
x
, and
z
z
z
the sum of the digits of
y
y
y
. Find
z
z
z
.
number theory
Russia