110nnnnn

If the first byte (8 bits) of an address is a class C address, it will have 110 in the first 3 bits. Since this 8 bit number is a binary number, each of the next 5 bits would be a 1 or a 0. That means the largest possible binary number for that first byte would be 11011111 or 223 in decimal (128+64+0+16+8+4+2+1). The smallest possible binary number for that first byte would be 11000000 or 192 in decimal (128+64+0+0+0+0+0+0).