SOLUTION: Anna leaves the house for school walking at the rate of 4kph. Two hours later, Elsa follows Anna at 4.5kph. How long will it take Elsa to over take Anna?

Question 1169509: Anna leaves the house for school walking at the rate of 4kph. Two hours later, Elsa follows Anna at 4.5kph. How long will it take Elsa to over take Anna?

Answer by ikleyn(52810)   (Show Source): You can put this solution on YOUR website!
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At the moment Elsa starts, Anna is 8 km ahead.     ( 8 km = 4 kph * 2 hours )

Beginning from this moment, the distance between them decreases at the rate of
        0.5 kph = 4.5 kph - 4 kph.

Hence, Anna will catch up Elsa in    = 16 hours.         ANSWER

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Solved.

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