You know that .

Distance km

Speed km/h

If he had driven km/hr faster, he would have reached in hours less time.

That means... Actual Time taken Time taken while driving km/h faster hours.

Now express as a single fraction:

Now multiply both sides by the denominator, .

Divide throughout by :

Now factorise:

Either (discard) or .

Check: So he was driving at km/h.

Time taken to drive at km/h hours.

Time taken to drive at km/h hours.

Difference in times hours.

at above poster.

I hope that helps.

ILoveMaths07.