If it takes 12 birds to eat 12 packets of food in 6 minutes that means it takes .5 minutes for 1 bird to eat 1 packet of food. 6÷12=.5
If there is 9 birds to eat 36 packets you first have to multiply the amount of birds times the rate it takes one to eat one packet. 9×.5=4.5 and with this now you know how many packets of food the group of 9 birds can eat per minute. Finally you divide the amount of packets by the amount of packets of food the group of 9 birds can eat per minute. 36÷4.5=8 And that's how they take 8 minutes to eat the 36 packets of food.
