<PRE><B>Question 389587</B>
A boy walks a certain distance at 9 km/h.
 He finds that if he increases his speed by 1/3, he would have saved 4/3 hours.
 Find the distances he walks
:
Let d = distance he walks
:
Find the increased speed: 9 + 1/3(9) = 12 km/hr
:
Write a time equation; time = dist/speed
:
9km/hr time - 12km/h time = 4/3 hrs
{{{d/9}}} - {{{d/12}}} = {{{4/3}}}
multiply by 36 to clear the denominators, results:
4d - 3d = 12(4)
d = 48 km is the distance
:
:
Check solution by finding the times
48/9 = 5.33 hrs
48/12= 4.00 hrs
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diff = 1.33 hrs which is 4/3 hrs

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