A farmer has C chickens. A sack of feed comes for 9 days. As the feedcost is increasing the farmer sells some chickens and retains 12 chicken. If he reduces thefeed quantity by 10% .Then he observes that the feed comes for 30 days. What is C?

C chickens can b fed for 9 days. So C chick can eat 1/9 in 1 day.
So 1 chick can eat (1/9C) in one day. After his reduction one chick gets to eat only 90% of what it used to eat in one day.
So new feed value=0.9*(1/9C) for 1day.but now he has only 12 chicks.
that means as per new rule feed is suitable for 12 chicks for 30 days.
i.e.
0.9*(1/9C)*12*30=1. Solve to get C=36
Ans:36