Answer:
it took him 3 hours to get to work
Step-by-step explanation:
For the first part of the trip, the executive covered a distance "d" in time 't" at 35 mph, therefore we can write that the time it took to get to the helicopter was:
[tex]t-\frac{d}{35}[/tex]
which if the distance is in miles, will render the time in hours.
We can write something similar for the second part of the trip", using the same "t" since it took the same time as for the first one, and using for distance 169.5 - d (since it is the distance to complete the total traveled distance :
[tex]t=\frac{169.5-d}{78}[/tex]
Now we equal those two equations because the time "t" is the same, and solve for "d":
[tex]\frac{d}{35} =\frac{169.5-d}{78} \\78\,d=35\,(169.5-d)\\78\,d=5932.5-35\,d\\(78+35)\,d=5932.5\\d=\frac{5932.5}{113} \\d=52.5[/tex]
Now, knowing the distance covered in the first trip, we can find the time of that first trip:
[tex]t=\frac{52.5}{35} =1.5\,\,hours[/tex]
Therefore, the time it took for thye total trip is: 1.5 h + 1.5 h = 3 hours
