Question

A photo of a painting measures 13" x 17" the scale factor is 1/3 what size is the painting

Answer 1

Given that the paint has a dimension of 13" by 17", it implies that:
width=13" and length=17"
The scale factor of the painting is 1/3. Thus the original size was as follows'
Width=13/(1/3)=39"
Length=17/(1/3)=51'
the answer is 39" by 51"