The IP addresses for the PCs and routers are as follows:

Device Interface IP address

A $192\mathrm{.}168\mathrm{.}1\mathrm{.}5$

B $192\mathrm{.}168\mathrm{.}1\mathrm{.}6$

C $192\mathrm{.}168\mathrm{.}1\mathrm{.}7$

D $192\mathrm{.}168\mathrm{.}5\mathrm{.}8$

E $192\mathrm{.}168\mathrm{.}5\mathrm{.}9$

R$1\mathrm{.}1192\mathrm{.}168\mathrm{.}1\mathrm{.}3$

R$1\mathrm{.}2192\mathrm{.}168\mathrm{.}2\mathrm{.}1$

R$2\mathrm{.}1192\mathrm{.}168\mathrm{.}2\mathrm{.}2$

R$2\mathrm{.}2192\mathrm{.}168\mathrm{.}5\mathrm{.}5$

Answer the following questions by filling in the blanks:

How many subnets are there in this network:

Answer:

$($fill in integer numbers only in the blanks$)$

Suppose the left hand switch is a subnet with the last byte as the host address. Write the subnet address in decimal shorthand format $($A$.$B$.$C$.$D$/$X$)$: