Determine the largest even positive integer that cannot be written as the sum of two odd composite positive integers.

38 is the answer

For an even integer over 38:

If it's 0 mod 3, then it equals 3*3+ an odd
multiple of 3;

If it's 1 mod 3, then it equals 5*5 + an
odd multiple of 3;

If it's 2 mod f 3, then
it's 35 plus an odd multiple of 3.

In all those cases there exist two composite addends.

**Therefore the largest
possible one is 38**.

38=1+37=3+35=5+33=7+31=9+29=11+27=13+25=

=15+23=17+21=19+19

In each of the above couples at least one number is a
prime.