MathDB

Let

S=\{1928,1929,1930,\cdots,1949\}.

We call one of

S

’s subset

M

is a red subset, if the sum of any two different elements of

M

isn’t divided by

4.

Let

x,y

be the number of the red subsets of

S

with

4

and

5

elements,respectively. Determine which of

x,y

is greater and prove that.

Problem Statement