ok so
2 digits even, last is odd
sum is 11
between 256 and 299
not 281
ok so we take 3 facts
sum is 11
between 256 and 299
2 are even
between 256 and 299, the first number is always 2
therefor
2+x+y=11
x+y=9
the other 2 numbers add up to 9
write all 2 ditgit numbers between 56 and 99 that add up to 9
63,72,81,90
not 281 so get rid of 81
and last diti is odd and first 2 are even so get rid of 72 and 90
therfor is it 63
263