Answer: 10 minutes
Step-by-step explanation:
Given : Time taken by Dodie to clean her hair salon = 15 minutes
Time taken by Ann to clean the hair salon = 30 minutes
Let t be the time taken by both of them if they work together, then we have
[tex]\dfrac{1}{t}=\dfrac{1}{15}+\dfrac{1}{30}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{2+1}{30}=\dfrac{3}{30}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{1}{10}\\\\\Rightarrow\ t=10[/tex]
Hence, it would take 10 minutes to clean the salon if both work together.