Question 7
Larry owns a cage that can hold a total of 15 peacocks and parrots. If the food box inside the cage is completely filled, the birds can consume all of it in 6 days. Later on, one parrot was added to the cage. The food box was full at the start and $\frac1{16}$ of the feeds is added every day. After exactly 9 days, the feed box was completely empty. It is known that the peacock eats twice as much feeds as the parrot does every day. Moreover, both kinds of birds eat a fixed amount of feeds every day. How many peacocks are there inside the cage?