length of the packet = 450 M Bytes
The data rate on the network is 2 MByte/s
the data rate on the link from the host to the bucket is X MByte/s
Transmission time of packet of length 450MB put in the bucket = (450 /X) sec
therefore , actual data sent on network in (450 /X) sec = network rate * (450 /X) = (450 /X) * 2 = (900/x) MB
Capacity of bucket is = 200 MB
450 - 900/X = 200
450 X - 900 = 200 X
250 X = 900
X = 3.6 MByte /sec
= (3.6 /8 ) Mbps
= 0.45 mbps