Question

How can 50 cows be tied on 9 pillars with an odd number on each pillar?

Answer 1

it is not possible, in any case either there will be a pillar in excess or less
or the no. of cows will be one less or one more
only when 0 is even.
The above is when you go by math.
Alternatively,
you could put any no. of cows on each pillar and paint an odd number on the pillar
The question says 'odd number on each pillar'