<PRE><B>Question 1038787</B>
B travels from home to school at 6km/h and returns same route at 8km/h in 70 minutes for entire joruney. What is the distance of school
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Avg speed of a round trip is similar to parallel flow and parallel resistors.
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Avg = 2*r1*r2/(r1+r2)
= 2*6*8/14 = 96/14 km/hr
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70 mins = 7/6 hours
RT distance = (48/7)*(7/6) = 8 km
4 km one way.
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I don&#39;t try to remember all the formulas there are, but this one is easy, only a factor of 2 difference from flow, work or resistance in parallel.</PRE>