Question

A car took 2 hrs to cover a certain distance at 45 kmph. It will take hr(s) to cover same distance at 90 kmph.

Answer 1

Since, the speed of the car has been increased , the time taken to cover the same distance should be less,
speed $\times$ time = distance
So,
A$\times$ B = constant
Let the time taken be $t$ hrs
$⟹45\times 2=90\times t$
$⟹t=1hr$
Therefore, the time taken to cover same distance at 90 kmph is 1 hour.