Answer: The customer spends 10 minutes at a booth.
Step-by-step explanation:
Let n= number of booths, [tex]\rho[/tex] = utilization, [tex]\lambda[/tex] = arrival rate, [tex]\mu=[/tex]Service rate
We know that
[tex]\rho=\dfrac{\lambda}{\mu\times n}[/tex]
As per given,
[tex]0.5=\dfrac{15}{\mu\times5}\\\\\Rightarrow\ \mu=\dfrac{15}{5\times0.5}\\\\\Rightarrow\ \mu=6[/tex]
Service rate = 6 customers per hour.
Time taken by each customer = [tex]\frac{1}{\mu}[/tex]
[tex]=\frac{1}{6} \ hours \ or\ \dfrac{60}{6}\ minutes\\\\=10 \ minutes[/tex]
Hence, the customer spends 10 minutes at a booth.