MathDB
Problems
Contests
International Contests
Baltic Way
2016 Baltic Way
11
11
Part of
2016 Baltic Way
Problems
(1)
PHP type problem
Source: Baltic Way 2016, Problem 11
11/5/2016
Set
A
A
A
consists of
2016
2016
2016
positive integers. All prime divisors of these numbers are smaller than
30.
30.
30.
Prove that there are four distinct numbers
a
,
b
,
c
a, b, c
a
,
b
,
c
and
d
d
d
in
A
A
A
such that
a
b
c
d
abcd
ab
c
d
is a perfect square.
combinatorics