Table:
0
A
B
C
D
E
F
G
H
1
Class
Leading bits
Size of network number bit field
Size of rest bit field
Number of networks
Addresses per network
Start address
End address
2
Class A
0
8
24
128 (2 7 )
16,777,216 (2 24 )
0.0.0.0
127.255.255.255
3
Class B
10
16
16
16,384 (2 14 )
65,536 (2 16 )
128.0.0.0
191.255.255.255
4
Class C
110
24
8
2,097,152 (2 21 )
256 (2 8 )
192.0.0.0
223.255.255.255
5
Class D ( multicast )
1110
not defined
not defined
not defined
not defined
224.0.0.0
239.255.255.255
6
Class E (reserved)
1111
not defined
not defined
not defined
not defined
240.0.0.0
255.255.255.255

Questions and formulas:
Question: What is the number of networks when the size of rest bit field is 8?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,D1=8),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H6,D2:D6=8),5))
Level: medium
Question: What is the start address when the network number bit field is 16?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,C1=16),7))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H6,C2:C6=16),7))
Level: medium
Question: What is the end address for the Class E (Reserved)?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,A1="class e (reserved)"),8))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H6,A2:A6="class e (reserved)"),8))
Level: medium
Question: What is the size of the rest bit field when the leading bits are more than 110 and the start address is 224.0.0.0?
Formula: LET(query1,LET(query1,FILTER(A1:H1,G1="224.0.0.0"),SUMMARIZE(CHOOSECOLS(query1,4),SUMX(CHOOSECOLS(query1,2)))),FILTER(query1,CHOOSECOLS(query1,2)>110))
Formula2: LET(query1,LET(query1,FILTER(A2:H6,G2:G6="224.0.0.0"),SUMMARIZE(CHOOSECOLS(query1,4),SUMX(CHOOSECOLS(query1,2)))),FILTER(query1,CHOOSECOLS(query1,2)>110))
Level: hard