Answer
given
Case 1-Speed of car 50 Km/h for 15 min
Case 2-Speed of car 85 Km/h for 19 min
Case 3 - Speed of car 60 km/h for 55 min
lunch break time = 25 min
a) total distance travel
we know,
distance = speed x time
[tex]D = 50 \times \dfrac{15}{60} + 85 \times \dfrac{19}{60} + 60\times \dfrac{55}{60}[/tex]
D = 94.42 Km
b) [tex]average\ speed = \dfrac{total\ distance}{total\ time}[/tex]
[tex]average\ speed = \dfrac{94.42}{\dfrac{15}{60}+\dfrac{19}{60}+\dfrac{55}{60}+\dfrac{25}{60}}[/tex]
[tex]average\ speed = 49.69\ km/h[/tex]
