<PRE><B>Question 696798</B>
The time taken by Arushi to cover 150 km was 2hrs and 30 min more than the time taken in return journey. If she returned at a speed of 10km/hr more than the speed of going,find her speed in each direction.
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Going DATA:
dist = 150 km ; rate = r km/hr ; time = 150/r hrs
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Return DATA:
dist = 150 km ; rate = r+10 km/hr ; time = 150/(r+10) hrs
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Equation:
time - time = 2.5 hrs
150/r - 150/(r+10) = 2.5 hrs
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150r + 150+10 - 150r = 2.5r(r+10)
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2.5r^2 + 25r - 1500 = 0
r^2 + 10r - 600 = 0
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Factor:
(r+30)(r-20) = 0
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Positive solution:
rate = 20 km/hr (going speed)
r + 10 = 30 km/hr (return speed)
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Cheers,
Stan H.
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