need step by step explanation with correct option answer as soon as possible

Mini-Scenario: Computer Lab Helpdesk Consider the following service process for the next two questions. Students arrive randomly at the help desk of the computer lab. There is only one service agent (i.e., lab assistant), and the time required for inquiry and problem solving varies from student to student. The average arrival rate is 12 students per hour, and the average service rate is 20 students per hour. How long is a student (arriving at the help desk of the lab) expected to be in the system? a. 0.125 minute O b. 0.9 minute O c. 1.5 minutes d. 7.5 minutes O e. 5 minutes With reference to the (Computer Lab Help Desk) Mini- Scenario in the previous question, what is the expected average number of students waiting in line? a. 0.5 student b. 0.9 students O c.0.6 students O d. 1.67 students e. 3.25 students