Table:
0
A
B
C
D
E
1
Prefix size
Network mask
Available subnets
Usable hosts per subnet
Total usable hosts
2
/24
255.255.255.0
1
254
254
3
/25
255.255.255.128
2
126
252
4
/26
255.255.255.192
4
62
248
5
/27
255.255.255.224
8
30
240
6
/28
255.255.255.240
16
14
224
7
/29
255.255.255.248
32
6
192
8
/30
255.255.255.252
64
2
128

Questions and formulas:
Question: When the network mask is 255.255.255.252 what is the prefix size?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="255.255.255.252"),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,B2:B8="255.255.255.252"),1))
Level: medium
Question: available subnets leading total is?
Formula: SUM(C1)
Formula2: SUM(C2:C8)
Level: easy
Question: When the network mask is  255.255.255.128 what is the lowest available subnet?
Formula: MINIFS(C1,B1,"255.255.255.128")
Formula2: MINIFS(C2:C8,B2:B8,"255.255.255.128")
Level: easy
Question: When the network mask is 255.255.255.224 what is the highest  total usable host?
Formula: MAXIFS(E1,B1,"255.255.255.224")
Formula2: MAXIFS(E2:E8,B2:B8,"255.255.255.224")
Level: easy