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 rest of the journey?

Answer 1

Dear student,

$$\begin{gathered} totaldis\tan ce=630km \\ totaltime=9hr \\ Case1: \\ dis\tan cetravelled=\frac{2}{3}\times 630=2\times 210=420km \\ speed=60km/hr \\ timetaken=\frac{dis\tan cetravelled}{speed} \\ =\frac{420}{60} \\ =7hr \\ Case2: \\ Dis\tan cetravelled=Totaldist.-Disttravelledincase1 \\ =630-420 \\ =210km \\ timetakenincase2=totaltime-timetakenincase1 \\ =9hr-7hr \\ =2hr \\ \therefore speedtakenin2ndcase=\frac{210}{2}=105km/hr \end{gathered}$$

Regards