Given :
Peter velocity , P = 30 mph .
Mitchell velocity , M = 40 mph .
Mitchell leaves 15 min later .
To Find :
If they drive along the same route how long will it take Mitchell to catch Peter.
Solution :
Distance covered by Peter in 15 min .
[tex]D = 30\times \dfrac{15}{60}=7.5\ miles[/tex]
Let , time taken is x .
So , distance covered b them is equal :
[tex]7.5+30\times x=40\times x\\\\x=\dfrac{7.5}{10}=0.75\ hours\\\\x=0.75\times 60\ min\\\\x=45\ min[/tex]
Therefore , time taken by them is 45 minutes .
Hence , this is the required solution .