Question

When the average speed is 60 km/hr the time required to cover a certain distance is one hour less than the time required to cover the same distance when the average speed is 40 km/hr. Find the distance.

Answer 1

Dear student
$$\begin{gathered} \mathrm{we}\mathrm{know}, \\ \mathrm{Distance}=\mathrm{Speed}\times \mathrm{Time} \\ \mathrm{So},\mathrm{according}\mathrm{to}\mathrm{Question} \\ 60\times \left(\mathrm{x}-1\right)=40\mathrm{x}\mathrm{where}\mathrm{x}\mathrm{hr}\mathrm{is}\mathrm{the}\mathrm{time} \\ \Rightarrow 60\mathrm{x}-60=40\mathrm{x} \\ \Rightarrow 20\mathrm{x}=60 \\ \Rightarrow \mathrm{x}=3 \\ \mathrm{So},\mathrm{the}\mathrm{distance}=40\times 3=120\mathrm{km} \end{gathered}$$
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