Consider the delay in sending a message of size $5$MB over a $7-$hop path in a circuit$-$switched network and in a $($lightly$-$loaded$)$ datagram packet$-$switched network. The circuit setup time is $0\mathrm{.}1$s$,$ the propagation delay is $0\mathrm{.}0001$s per hop and the data rate at each node is $2\mathrm{.}4$Mb$/$s$.$ What is the largest packet size in Bytes that is needed so that the packet switching is not slower than the circuit switching?

Assume that the message length of $5$MB is a multiple of the packet size. You do not have to take into account the packet headers and you can assume the packet$-$switched network is lightly loaded.

The answer to this question is $5000$ but I$\text{'}$m unsure of how that was gotten