Respuesta :
you would use 1.5 packets, but that requires 2 packets.
1 packet in total would feed 8 people, and half of another would feed an extra 4. 4+8 = 12.
you would need 1 packet and a half pack to feed 12 people. 1 packets would feed 8 people and the half packet would feed the other 4 feeding up to 12 people in total.