Answer:
Average speed of car is 45 [tex]\frac{km}{h}[/tex].
Explanation:
Average speed for entire 25 km is 22[tex]\frac{km}{h}[/tex]
Average speed = [tex]\frac{Total distance}{Total time}[/tex]
22 = [tex]\frac{25}{Total time}[/tex]
Total time = [tex]\frac{25}{22}[/tex]
Total time = 1.136 hour
Time for first 7 km is given by t,
t = [tex]\frac{distance}{speed}[/tex]
t = [tex]\frac{7}{9.5}[/tex]
t = 0.736 hour
Thus, time required for next 18 km is
T = Total time - t
T = 1.136 - 0.736
T = 0.4 hour
Hence, average speed of car for 18 km is given by,
Average speed, v = [tex]\frac{distance}{time}[/tex]
v = 45 [tex]\frac{km}{h}[/tex]
Average speed of car is 45 [tex]\frac{km}{h}[/tex].
