A user has the option to choose between two

of network channels to transfer $1$ file $($x Kbyte$).$ One channel has

$10$ms propagation delay and $20$Mbit$/$see speed while the other channel

it has a propagation delay of $5$ ms and a speed of $10$Mbit$/$sec$.$ Calculate when

it is precisely in the best interests of the particular user to choose it

first channel. Delays due to processing and waiting

are considered negligible.