1.5 MBytes / 1500 Bytes = 1500 message bytes
The message overhead includes: TCP: 20 bytes of header & IP: 20 bytes of header
1500 - 20 -20 = 1460 bytes
1.5 Mbyte / 1460 byte = 1027.4, therefore 1028 blocks are needed to transfer the file.
Overhead = ((1028 x 1500 - 1.5M)/1.5M) x 100 = 2.8%