Solution:
we are given that
Two trains began their trip from the same station at 8:00 a.m. One train travelled North at a rate of 44 mph and the other travelled South at a rate of 46 mph.
we have been asked to find
What time will it be when the trains are 405 miles apart?
As we know that

Suppose they are 405 miles apart after t hours.
So using this formula we can write

Hence they will be 405 miles apart by 8+4.5=12.5PM.