Question

in an ipv4 datagram, the m bit is 0, the value of hlen is 10, the value of total length is 400 and the fragment offset value is 300. the position of the datagram, the sequence numbers of the first and the last bytes of the payload, respectively are

Answer 1

M=0M=0 meaning no more fragments after this. Hence, its the last fragment. 

IHL = internet header length = 10×4=40B10×4=40Bcoz 44 is the scaling factor for this field. 
Total Length = 400B400B 
Payload size = Total length - Header length = 400−40=360B400−40=360B 

fragment offset = 300×8=2400B300×8=2400B = represents how many Bytes are before this. 88is the scaling factor here. 
∴∴ the first byte # = 24002400 

Last byte # = first byte # + total bytes in payload - 1 = 2400+360−1=2759


I hope you have Understood !