Answer:
Number of stores=3
Number of dress=1
Probability of buying the dress from any of the three stores
[tex]\rightarrow\frac{\text{Total Favorable Outcome}}{\text{Total Possible Outcome}}\\\\=\frac{1}{3}[/tex]
→She should buy the dress from that store where the price of the dress is lowest and least distance from her office to save time and Energy.