The average length of time that a customer waits in line for service is $W ( x , y ) = \frac { 1 } { x - y } , x y$ where $y$ is the average arrival rate, written as the number of customers per unit of time, and $x$ is the average service rate, written in the same units. Evaluate $W ( 18,6 ) .$ Note: $x$ and $y$ are given as the number of customers per hour.
A) $7 \mathrm {~min}$
B) $5 \mathrm {~min}$
C) $3 \mathrm {~min}$
D) $4 \mathrm {~min}$
E) $6 \mathrm {~min}$

Question

The average length of time that a customer waits in line for service is $W ( x , y ) = \frac { 1 } { x - y } , x > y$ where $y$ is the average arrival rate, written as the number of customers per unit of time, and $x$ is the average service rate, written in the same units. Evaluate $W ( 18,6 ) .$ Note: $x$ and $y$ are given as the number of customers per hour.
A) $7 \mathrm {~min}$
B) $5 \mathrm {~min}$
C) $3 \mathrm {~min}$
D) $4 \mathrm {~min}$
E) $6 \mathrm {~min}$

Quizplus · Accepted Answer

The Answer of The average length of time that a customer waits in line for service is $W ( x , y ) = \frac { 1 } { x - y } , x > y$ where $y$ is the average arrival rate, written as the number of customers per unit of time, and $x$ is the average service rate, written in the same units. Evaluate $W ( 18,6 ) .$ Note: $x$ and $y$ are given as the number of customers per hour.
A) $7 \mathrm {~min}$
B) $5 \mathrm {~min}$
C) $3 \mathrm {~min}$
D) $4 \mathrm {~min}$
E) $6 \mathrm {~min}$

The Average Length of Time That a Customer Waits in Line