A car travels from Gwalior to Jhansi at 60 km/hr and returns at 80 km/hr. If the total travel time is 3.5 hours, what is the one-way distance?
120 km
Let the one-way distance be \(d\) km.
Time taken to go \(= \frac{d}{60}\) hours, and time taken to return \(= \frac{d}{80}\) hours.
Total time: \(\frac{d}{60} + \frac{d}{80} = 3.5\).
Taking the LCM of 60 and 80 (=240): \(\frac{4d + 3d}{240} = 3.5 \Rightarrow \frac{7d}{240} = 3.5\).
\(7d = 840 \Rightarrow d = 120\).
Hence, the one-way distance is 120 km.
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