Calculations involving distance, speed and time can be worked out using formulae. When doing these calculations, the units used should be consistent.
Part of MathsTime
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Joanna drives for \(400km\) at an average speed of \(80km/h\).
How long was her journey?
\(Time = \frac{{Distance}}{{Speed}}\)
\(Time = \frac{{400}}{{80}}\)
\(Time = 5hrs\)
Joanna's journey was \(5hrs\) long.
Scott cycles at \(4mph\) and covers a distance of \(13\,miles\).
How long does his journey take?
\(Time = \frac{{13}}{4}\)
\(Time = 3.25hrs\)
But we don't write \(3.25\,hours\). The answer should be in hours and minutes.
So the answer is \(3hrs\,15\,mins\).