MathDB
Problems
Contests
National and Regional Contests
Canada Contests
Canada National Olympiad
1978 Canada National Olympiad
1
1
Part of
1978 Canada National Olympiad
Problems
(1)
Find units digit of n^2 from tens digit
Source: Canadian Mathematical Olympiad - 1978 - Problem 1.
5/14/2011
Let
n
n
n
be an integer. If the tens digit of
n
2
n^2
n
2
is 7, what is the units digit of
n
2
n^2
n
2
?
modular arithmetic
number theory proposed
number theory