Answer:
17 packets.
Step-by-step explanation:
One of the yellow packets is the sixth from the left, then there are 5 packets before it.
The other packet is the eighth from the right, then there are 7 packets behind it.
Between the two yellow gift packets there are three differently colored packages.
Now count all packets:
5 + 1 (1st yellow) + 3 + 1 (2nd yellow) + 7 = 17 packets.