Respuesta :

3:15 and I know this because you subtract 3 hours from 7:45 which gets you 3:45 and you subtract 30 from 45 to get 3:15.
3:25 (not sure sorry) but, the question says that "in three hours" it will be 7:45 so 7-3=4 so it is currently 4:45 now they asked "what time was it 1/2 hour ago." so now 4:45 -> 3:25 or 3:50.