<PRE><B>Question 667186</B>
 a man cycled for some time at 16 km/h and returned at 15 km/h . the total time taken was 7 3/4 hours . find the total distance he cycled ?
:
Let d = the one-way distance
:
Write a time equation, time = dist /speed; change 7{{{3/4}}} to 7.75 hrs
:
{{{d/16}}} + {{{d/15}}} = 7.75
Multiply by 16*15; 240:
15d + 16d = 240(7.75)
31d = 1860
d = {{{1860/31}}}
d = 60 km
:
Find the total distance he cycled?
2(60) = 120 km
:
:
Check this by finding the time each way
60/15 = 4 hrs
60/16 = 3.75 hrs
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total time 7.75 hrs</PRE>