If the buses are travelling the same distance
Then
45 {Speed of Bus 1}×T1{time taken by bus 1}
60 {Speed of Bus 2}×T2{time taken by bus 2}
T2 = (T1- (11/2)) hrs
Substitute T2 with this info
We will get T1 as 22hrs
So the distance becomes T1 × 45 = 990Km