Computer Networks

Question

Given answer 

7^th = 30

8^th = c

 

How??

 

Comments

@Abhrajyoti00  

in the 7^th )

24 = 00011000

This 3 bit represent host id part, so host per subnet = $2^{3}$ -2 = 6.

in the 8^th )

@jugnu1337 answer seems to be correct.

but 

number of cable connected to host are 90. How do you come to conclusion that each cable represent different network. I mine with 90 cable 90 host can be represent of same network.

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@Abhrajyoti00 how it is correct?

The number of bits in HID can be 1 bit or 2 bit or 3 bit.

Answer 1

8.

no of  cable connected to the host = 90  which contain 2^7 no of bit which is fixed   {2^6 < 90 so took 2^7}

as given it is class B address  so    255.255.xxxxxxxx.xxxxxxxx

255.255.11111110.0000000   {in 3rd octant 7 bit fixed for subnet)   now highlight bit use for host

which contain 2^9 bit = 512  but in this   address which is all zero {network address} and last address all 1’s which is broadcast add.

 so after removing them 512-2  = 510