.
Let x be the distance from the apartment building to the parking.
Then we have the time equation
Betty's total travel time = Carl's total travel rime
=
Multiply both sides by 45*5*40*6
5*40*6x + 45*40*6*(65-x) = 45*5*6*x + 45*5*40*(65-x)
5*40*6x - 45*40*6x - 45*5*6x + 45*5*40x = 45*5*40*65 - 45*40*6*65
(5*40*6 - 45*40*6 - 45*5*6 + 45*5*40)x = 45*5*40*65 - 45*40*6*65
-1950x = -117000
x = {{(-117000)/(-1950)}}} = 60.
Thus we found the distance x = 60 miles.
Hence, Betty spends + hours = 1 hour 20 minutes + 1 hour = 2 hours and 20 minutes.
To check, Carl spends the same time + hours = 1 hour 30 minutes + 50 minutes = 2 hours and 20 minutes.
Hence, they both arrive to work at 8:20 am.