Host A wants to send a file of size $1$ Mb $($mega$-$bits$)$ to Host B$.$ They are connected via $2$ routers $(3($serial$)$ communication links between Hosts A and B$).$ The capacities of $3$ communication links are $10$ Mbps$,20$ Mbps$,$ and $1$ Mbps$.$ How long does it take for the file to be transmitted from Host A to Host B$?$ Consider no propagation delay, processing delay, and queueing delay.