Math CentralQuandaries & Queries


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 $v.$


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS