Maths and Physics in Oxford (OAT) Skills Assessment?

[CadetPilot]

Aircraft 1 travels at 175 nm an hour.
That is 131 nm for the 45 minutes.

The difference between the speeds of both aircrafts are 60 Kts.

60 goes into 131 how many times?
2.11

Add that to your time 10.45, which gives you 12.56

Much easier!