Arun is travelling on his cycle and has calculated to reach point A at 2 pm if he travels at 10 kmph. He will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 pm?
8kmph
10 kmph
12 kmph
14 kmph
Explanation:
Let the distance be x km
Travelling at 10 kmph, Arun will reach point A at 2 pm.
Travelling at 15 kmph, Arun will reach point A 12 noon.
Therefore, time taken when travelling at 10 km - time taken when travelling at 15 km =2hours
⇒x/10−x/15=2
⇒3x−2x=2×30
⇒x=60
Time needed if travelled at 10 kmph =60/10=6 hours
Therefore, to reach at 1 pm, his travelling time must be (6−1)=5 hours.
Hence, required speed =60/5=12 kmph
Let the distance be x km
Travelling at 10 kmph, Arun will reach point A at 2 pm.
Travelling at 15 kmph, Arun will reach point A 12 noon.
Therefore, time taken when travelling at 10 km - time taken when travelling at 15 km =2hours
⇒x/10−x/15=2
⇒3x−2x=2×30
⇒x=60
Time needed if travelled at 10 kmph =60/10=6 hours
Therefore, to reach at 1 pm, his travelling time must be (6−1)=5 hours.
Hence, required speed =60/5=12 kmph