Question

A customer asks for a block of 64 addresses from ISP. If ISP designs the address in classless address scheme, what range of address can be provided to the customer in the block 185.10.X.X/16 

Answer 1

The number of addresses is determined as follows:

$2^h-2$

$2^7-2=126$, where h is a number of host bits. So we have 7 host bits and the address range:

185.10.0.129 - 185.10.0.254.