9/2 that the answer ok ok
Answer: 14
The number to the right of the decimal point is either 5 or greater than that, so the 13 is increased by 1 which results in 14.
If you divide 537 in to 12 groups. each group would have 44 cookies and you would have 9 left.
1, 3, 5, 7, 9 ......
notice, there are consecutive odd integers, every other number
skip one, another, skip one, another and so on
so, from 1 to 3, is 1 + 2 =3
5 is 3 +2
7 is 5+2
and so on
let us pick an odd integer, hmmm say "a"
to find the next odd one, it'd be "a + 2" of course :)
we know their sum is 316
so

once you found "a", the next one is, well, "a + 2" :)