There are M number of packets.
Since each packet contains L bits and 4h bits are for header, so,
Total number of bits in a packet are (L+4h).
But total number of packets are M.
Total number of bits to be transmitted becomes M*(L+4h).
When we need to transmit it only one link having bandwidth R bps,
We get, M*(L+4h)/R.
But since we have Q such links,
Time taken in second = Q*M*(L+4h)/R.
Correct me if I am wrong.