Two runner start running together for a certain distance, one at 5 km/h and another at 8 km/h. The former arrives one and half an hour before the latter. The distance in Km is :
A. 12 km
B. 20 km
C. 25 km
D. 36 km
Answer: Option B
Solution (By Examveda Team)
$$\eqalign{ & \text{Let }x\text{ be the distance, then} \cr & \frac{x}{5} - \frac{x}{8} = \frac{3}{2} \cr & \Rightarrow \frac{8x - 5x}{40} = \frac{3}{2} \cr & \Rightarrow \frac{3x}{40} = \frac{3}{2} \cr & \therefore x = 20\,{\text{km}} \cr} $$This Question Belongs to Arithmetic Ability >> Speed Time And Distance
Their is change in values instead of 5kmph it is 8 and for 3kmph it is 5 rest is same....and this solution is wrong they just copied it from....supporting material
perhaps, it's a typing mistake.
Another one runs at speed of 3 km/h and not at 8 km/h.