Question 569575
 Two cyclists start from the same
place  in  opposite  directions.
One  goes  towards  North  at  18
kmph   and   the   other   goes
towards  South  at  20  kmph.
What  time  will  they  take  to  be
47.5 km apart ?
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The speeds are added
18 + 20 = 38 km/hr
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d = r*t
t = d/r