I need help answering this question this is non graded and on a practice exam.

Triage is considering creating two separate lines, the first for patients with surnames starting with a letter in the range A-M, the second for N-Z. Each line would have a Triage nurse dedicated to serve only that line of patients. Assume that average patient arrival rate for each line will be the same and both will have poisson pattern. What is the new expected waiting time in minutes? Please keep precision at 3 decimals.