



 
Hi Wendy, The secret to success in this type of problem is in the translation of information into a workable equation. We always begin by choosing a variable to work with and saying what it represents, usually one of the numbers we are trying to find.
Next we use one of the relationships between Petra and her mother to conclude the mother's age.
Next we use the other relationship between Petra and her mother to set up an equation.
Can you finish it from here? Leeanne  


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