Router XX has forwarding table:
Network/Mask Next_Hop
170.211.220.0/24 deliver directly
170.211.220.0/22 184.129.184.1
170.211.208.0/22 184.129.170.1
170.211.216.0/21 184.129.178.1
170.211.216.0/23 184.129.172.1
0.0.0.0/0 184.129.178.1

Explain what router XX will do with packets with the following destination addresses. Be sure to use longest prefix routing.
a. 170.211.218.17
b. 170.211.220.108
c. 170.211.222.44
d. 170.211.218.128
e. 184.129.184.1
f. 170.211.213.54
g. 170.211.211.20
h. 170.211.217.17
i. 170.212.216.5
j. 170.211.219.32

Any help would be much appreciated! I'm having trouble figuring out where/what these will be doing/going

You can use this information to help you with figuring out which entry to use in the routing table. Since you mentioned longest prefix routing, the most specific entry with the highest subnet mask will be used.

170.211.220.0 /24 170.211.220.1 - 170.211.220.254
170.211.220.1 /22 170.211.220.1 - 170.211.223.254
170.211.208.0 /22 170.211.208.1 - 170.211.211.254
170.211.216.0 /21 170.211.216.1 - 170.211.223.254
170.211.216.0 /23 170.211.216.1 - 170.211.217.254

For the following destination addresses, the packets will go to the following interface:

a. 170.211.218.17 - 184.129.178.1
b. 170.211.220.108 - directly
c. 170.211.222.44 - 184.129.184.1
d. 170.211.218.128 - 184.129.178.1
e. 184.129.184.1 - 184.129.178.1
f. 170.211.213.54 - 184.129.178.1
g. 170.211.211.20 - 184.129.170.1
h. 170.211.217.17 - 184.129.172.1
i. 170.212.216.5 - 184.129.178.1
j. 170.211.219.32 - 184.129.178.1

Cool thanks so much for your help! Now I can do the rest of them with a breeze, thanks again :) !

Not a problem. Glad to hear this info helped.