192.168.187.233 /27...........( based on IP, it lies in 3rd octet...... so that BLOCK SIZE=32 )

here, C.I.D.R= /27.................... its shows that network portion is 27 (it means it lies in 4th octet )

so, we need to do modification in 4th octet ,  as per the given IP, 4th octet value is 233..

now, we need to divide the 233 by block size (32) and just consider only quotient and leave remainder..   i,e,

32) 233 ( 3

      224

-----------------

        9

-----------------

now , multiply dividend * quotient = 32*3= 224 (you will get)

so our NETWORK ID becomes:   192.168.187.224              // your given IP is 192.168.187.233

1st HOST IP start from== 192.168.187.225

2nd host IP :  192.168.187.226,, similarly others

your BROADCAST ID becomes:: 192.168.187.255

total number of host become= 30

host range== 192.168.187.225 to 192.168.187.254 , but your n/w id( 192.168.187.224 )  and broadcast id ( 192.168.187.255 ) will be.

i hope that you will understand...... still if u have any confusion then text me in comment box.. i will try to clr it..