Class B Sub netting

Example:
IP address 140.80.1.0
Subnet mask 255.255.240.0
240(10)-> 11110000(2)
Here n=4 (Because 148.80.1.0-> 11111111.11111111.11110000.00000000)
m= 12 (Because 148.80.1.0-> 11111111.11111111.11110000.00000000)
Maximum no. of combinations -> 2n = 24 = 16
Max no. of subnets -> 2n-2 = 14
Max no. of hosts/subnet -> 2m-2 =212-2 = 4096-2 =4094

Number of combinations (16)
00000000 = 0 (This is not used for assigning IP address)
00010000 = 16
00100000 = 32
00110000 = 48
01000000 = 64
01010000 = 80
01100000 = 96
01110000 = 112
10000000 = 128