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 Question from Zander: A lady drives 180km from her wine farm to Ceres. On her return (at night) she drove 30km/h slower. Her return takes one hour longer. At what speed did she drive home?

Hi Zander,

Suppose that the time it taker her to drive to Ceres is $t$ hours and she drives at a rate of $v$ kilometers per hour. Since rate is distance divided by time

$v = \frac{180}{t} \mbox{ or equivalently } 180= t \times {v}.$

For the return trip the time it takes is $t + 1$ hours and the speed is $v - 30$ kilometers per hour. Us the fact that rate is distance divided by time for the return trip to write a second equation.

Solve these equations for $v.$

Penny

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