Gce Model Questions Vol1 2021 Computer Studies Question 22

A school needs to transfer a 500 MB file to a remote server. Two internet connections are available: - Connection A: latency \(L_{A}=50\) ms, bandwidth \(B_{A}=20\) Mbps. - Connection B: latency \(L_{B}=120\) ms, bandwidth \(B_{B}=50\) Mbps. The file may be split into two parts; part of size \(x\) MB is sent over connection A and the remaining \(500-x\) MB over connection B, with both transfers occurring simultaneously. The transfer time for a part sent over a connection is \(T = L + \dfrac{\text{size (in megabits)}}{B}\). Determine the value of \(x\) (in megabytes) that minimises the total transfer time, and compute that minimum time (in seconds). Give \(x\) to the nearest megabyte and the time to one decimal place.