Ram travels a distance of 336 km by car at uniform speed. If the speed of the car had been 6 km/h less, then he would have taken 1 hour more for the same journey. What is the speed of his car?

Let the speed of the car be x km/h.

∴Time taken to complete the journey = $\frac{336}{x}h$

If the speed of the car is decreased by 6 km/h, then new speed = (x − 6) km/h.

Then, time taken = $\frac{336}{x-6}h$ 

By the given condition,

$$\begin{gathered} \frac{336}{x-6}=\frac{336}{x}+1 \\ \Rightarrow \frac{336}{x-6}=\frac{336+x}{x} \end{gathered}$$

⇒ 336x = (336 + x) (x − 6)

⇒ 336x = 336x − 2016 + x² − 6x

⇒ x² − 6x − 2016 = 0

⇒ x² − 48x + 42x − 2016 = 0

⇒ x(x − 48) + 42(x − 48) = 0

⇒ (x − 48) (x + 42) = 0

⇒ x = 48 or x = − 42

As speed cannot be negative, x = − 42 is neglected.

⇒ x = 48

Thus, the speed of the car is 48 km/h.