Question

A car cover a certain distance in 10 hours at speed of 48 km/h by how much should its speed be increased so that it takes only 8 hours to cover the same distance

Answer 1

Let the distance be x
Then
$speed = \frac{distance}{time } \\ 48 = \frac{x}{10} \\ x = 480 \\ now \: let \: the \: speed \: after \: increasng \: is \\y \: then \\ \: \frac{480}{8} = y \\ y = 60 \: \\ hence \: speed \: should \: be \: increased\\by \: 12km {hr}^{ - 1}$