Answer:
21.38 minutes
Explanation:
the total number served = 101
teh number of hours that is spent in serving from 11.30 to 1.30 = 2 hours
Lq = average number of those that are in line = 18 customers
from here we are to find the flow rate
=
= 101/2 = 50.5
the average time in waiting =
Lq/flow rate
= 18/50.5
= 0.3564 hours
convert to minutes = 0.3564 * 60 minutes
= 21.38 minutes