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)
$$\eqalign{ & \text{Let }x\text{ be the distance, then} \cr & \frac{x}{5} - \frac{x}{8} = \frac{3}{2} \cr & \Rightarrow \frac{8x - 5x}{40} = \frac{3}{2} \cr & \Rightarrow \frac{3x}{40} = \frac{3}{2} \cr & \therefore x = 20\,{\text{km}} \cr} $$Join The Discussion
Comments ( 3 )
Related Questions on Speed Time and Distance
A. 48 min.
B. 60 min.
C. 42 min.
D. 62 min.
E. 66 min.
A. 262.4 km
B. 260 km
C. 283.33 km
D. 275 km
E. None of these
A. 4 hours
B. 4 hours 30 min.
C. 4 hours 45 min.
D. 5 hours
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.