To determine how many customers can be served in 2 hours, we first calculate the rate of customers served per minute.
Given that 6 customers are served in 30 minutes, we find the rate of customers served per minute:
\[ \text{Rate} = \frac{6 \text{ customers}}{30 \text{ minutes}} = \frac{1 \text{ customer}}{5 \text{ minutes}} \]
Next, we convert 2 hours into minutes:
\[ 2 \text{ hours} = 2 \times 60 \text{ minutes} = 120 \text{ minutes} \]
With the rate of 1 customer per 5 minutes, we can find out how many customers can be served in 120 minutes:
\[ \text{Number of customers served} = \frac{120 \text{ minutes}}{5 \text{ minutes/customer}} = 24 \text{ customers} \]
Thus, the man can serve 24 customers in 2 hours.