Question

A car can finish a certain journey in 10 hours at a speed of 48 km per hr. In order to cover the same distance in 8 hours, how much the speed be increased by? 
1. 12 km per hr.
2. 14 km per hr.
3. 16 km per hr.
4. 18 km per hr.

Answer 1

Correct Answer - Option 1 : 12 km per hr.

Given

Total time is taken whole journey = 10 hrs.

The speed at whole journey = 48 km per hr.

Formuls

∴ Distance = Speed × Times 

∴ Distance = 48 × 10

= 480 kms

Now, this distance of 480 km is to be covered in 8 hours. Hence, the required speed

= 480/8 = 60 km pe hr

\(∴ \) Increase in speed = 60 - 48

= 12 km per hr.