Question

Vijay covers a part of the journey at 20 km/h and the remaining at 10 km/h, taking a total of 3 hours to cover a distance of 50 km. For how many hours did he drive at a speed of 20 km/h?

• A. 2

Answer 1

The correct option is A 2

Let the hours driven at a speed of 20 km/h be x hr.
So hours driven at the speed of 10 km/h = (3 - x) hr

$\text{Distance}=\text{Speed}\times \text{Time}$

Distance travelled at a speed of 20 km/ hr is 20x km.
Distance travelled at a speed of 10 km/ hr is 10(3-x) km.
Total distance covered is 50 km.

So,
$20\text{x}+10(3-\text{x})=5020\text{x}+30-10\text{x}=5010\text{x}=20\text{x}=2\text{hr}$