first find out what the question is actually asking.
what *percentage* (an integer from 0 to 100) of the time it takes to receive the file is spent in connection setup?
total time to receive a file = time for setup+time to send request for data and receive the data.
time for connection setup=send a SYN packet+receiveACK=100ms(1RTT it is)
time to send reqeest for data and receive data=paketise the request+send request+receiver packetisisng the data+send the data=1ms+100ms(1RTT it is)+1ms=202ms
(as the segment size is 1.4kB and required data size is also 1.4kB, so we will not be needing more than 2 packets. and also window size is 2 packets, hence 1 RTT is enough for the sender to receive the data)
calculating time for connection setup/total time to receive data(i.e connection setup + data transmission)=100/202~0.495~49.5%.