A journey of 900 km is completed in 11 h. If two-fifth of the journey is completed at the speed of 60 km/h. at what speed ( in km/h) is the remaining journey completed?
Answer & explanation
Correct answer: option 1
total distance = 900 km
Total time = 11 hours
\(\frac{2}{5}\) th of totaal distance = \(\frac{2}{5}\) × 900 = 360 km
Time taken to cover 360 km with 60 km/h = \(\frac{Distance}{Speed}\)
= \(\frac{360}{60}\) = 6 hours
Remaining time = 11 - 6 = 5 hours
Remaining time = 900 - 360 = 540 km
Speed required to cover 540 km in 5 hours = \(\frac{Distance}{Time}\)
= \(\frac{540}{5}\)
= 108 km/h