Ram travelled from a place Z to P at an average speed of 130 km/h. He travelled the first 75% of the distance in two third of the time and rest at an average speed of X km/h. The value of x/2 is.

Answer: Option B

Let the distance be 400 km
Then time taken by him = $$\frac{400}{130}$$
75% of distance is = 300 km
Time taken by him to complete the distance of 300 km $$=\frac{400}{130}\times \frac{2}{3}=\frac{80}{39}$$
Rest distance = 100 km
Time taken by him $$=\frac{400}{130}-\frac{80}{39}=\frac{40}{39}\text{ h}$$
According to the question,
$$\begin{array}{rl}& \frac{100}{\frac{40}{39}}=x\\ & x=\frac{390}{4}\\ & \therefore \frac{x}{2}=\frac{390}{8}=48.75\end{array}$$