Question

Rahim rode his motorbike for a distance of 30 km from his house to the General Hospital of Muar. If he incresed his average speed by 10 km / h, the time he takes to complete his journey will be reduced by 30 minutes. Calculate his initial average speed. pls help to solve it..

Answer 1

the first journey, we can write:
\[d = {v_0}t\]
where \(d=30\)Km, and \(v_0\) is the average speed, \(t\) is time needed to complete the journey
for second time, we can write this:
\[d = \left( {{v_0} + 10} \right)\left( {t - 0.5} \right)\]
being \(30\) minutes = \(0.5\) hours
so we have to solve this system, with respect to \(v_0\):
\[\left\{ \begin{gathered}
d = {v_0}t \hfill \\
d = \left( {{v_0} + 10} \right)\left( {t - 0.5} \right) \hfill \\
\end{gathered} \right.\]
where \(d=10\) Km

Answer 2

oops.. \(d=30\) Km

Answer 3

tq