75nm at original ground
speed (115kts) would take 39.1 minutes.
Aircraft has covered 75nm
in 40.6 minutes = ground speed 111kts.
Remaining distance to run
is 250 – 75 = 175nm and at revised ground speed of 111kts this will take 94.6
minutes.
Total elapsed time = 40.6
+ 94.6 = 135.2 minutes (2h15m).
Departure time is 0900
add elapsed time 2h15m, ETA = 1115.