Question

A bus covers $630$ km in $9$ h. If it completes the first two thirds of the journey at $60$ km/h, calculate its speed for the rest of the journey.

Answer 1

$2/3$ journey $=\frac{2}{3}\times 630=2\times 210=420$km

Time for $2/3$ journey $=\frac{distance}{speed}=\frac{420}{60}=7hr$

$\Rightarrow$ Time for rest of journey $=2$hr

$\Rightarrow$ Speed for rest of journey $=\frac{Distance}{time}=\frac{210}{2}=105$km/n.