A man performs 3/5 of the total journey by rail, 7/20 by bus and the remaining 6.5 km on foot. His total journey is :

Answer: Option D

Let the total journey be x km
Then,
$$\begin{array}{rl}& \iff \frac{3x}{5}+\frac{7x}{20}+6.5=x\\ & \iff \frac{12x+7x+20\times 6.5}{20}=x\\ & \iff 12x+7x+20\times 6.5=20x\\ & \iff x=130\text{ km}\end{array}$$