Time = Distance ÷ Speed

Captain Furball

I run 3km at 10kmph how long does it take me?

60/10 = 6 * 3 = 18
answer is 18 minutes.

Is that the right way of doing it?

The formula says divide speed by distance.

amacachi

Captain Furball wrote: »

I run 3km at 10kmph how long does it take me?

60/10 = 6 * 3 = 18
answer is 18 minutes.

Is that the right way of doing it?

The formula says divide speed by distance.

You switched from hours to minutes. If you divide the distance (3) by the speed (10) you get 0.3 hours. Which is 18 minutes.

Your way works by converting to minutes, dividing by the speed to get how long 1km takes to cover, then multiplying by the number of km. That method could get awkward when you can't easily divide the minutes etc.

Nietzschean

It does.. so the direct formula is (units in brackets)

T(hr) = 3(km) / 10 (km/hr)

->
hr = km / (km/hr) = (km / km) * hr = hr
T = 3 / 10 = 0.3 hr

So from the equation that would be the direct result, but 0.3 of 1hr is 18minutes. So your arriving at the correct result, but hopefully that'll kind of illustrate better how the equation as implied works.

Captain Furball

I was doing it wrong,but getting the correct answer.
I forgot all about using the hour.I'm terrible at maths, but at least i understand it now.
Cheers lads.