Question

Distance between two stations $P$ and $Q$ is $510km$. Two cars start simultaneously from
$P$ and $Q$ towards each other and the distance between them after $8$ hours is $30km$. If the speed of one car is less than the other by $20km/hr$, then the speed of one car can be

• A. $40km/hr$
• B. $52km/hr$
• C. $60km/hr$
• D. $48km/hr$

Answer 1

The correct option is A $40km/hr$

Let the speed of faster car be $xkm/hr$ speed of other $=(x-20)km/hr$ According to the question
$8x+8(x-20)+30=510$
$\Rightarrow 8x+8x-160+30=510$
$\Rightarrow 16x-130=510$
$\Rightarrow 16x=640$
$\Rightarrow x=40km/hr$