From the information given in the question, we are informed that Flora's car is 59/100 of a meter longer than Sally's car while Sally's car is 2/10 of a meter longer than Trevor's car.
The length of Flora's car than Trevor's car will be the addition of 59/100 and 2/10. This will be:
In the quote, "but six dollars per pound are more money than I can afford!" it should be, "but six dollar per pound <em>is</em> more money than I can afford!"