For these network segments: 172.168.16.0, 172.168.17.0, 172.168.18.0, 172.168.19.0, which of the following network segments is best used 172.168.16.0/21 、172.168.17.0/21 、172.168.16.0/22 、172.168.16.0/23 Please write a detailed solution, Which network segment is best used to implement routing aggregation?

For these network segments: 172.168.16.0, 172.168.17.0, 172.168.18.0, 172.168.19.0, which of the following network segments is best used 172.168.16.0/21 、172.168.17.0/21 、172.168.16.0/22 、172.168.16.0/23 Please write a detailed solution, Which network segment is best used to implement routing aggregation?

172.168.16.0/21: the 21 bit subnet mask contains 8 class C subnets (172.168.16 ~ 172.168.23.255), which means that there are 2046 hosts. The network is obviously too large. 172.168.17.0/21: serious error, because the 21 bit subnet mask does not have such a network segment. 172.168.16.0/22:22 bit subnet mask contains 4

A simple method to calculate 18.5 times 6.2 times 0.31

18.5×6.2×0.31
=18.5×20×0.31×0.31
=370×0.31×0.31
=370×0.1961
=35.557

(999+17/18)×(-9)

(1000-1/18)*(-9)=0.5-9000=-8999.5

999×27+333×19 =

999 + 333 + 19