In the service department of the Glenn-Mark Auto Agency, mechanics requiring parts for auto repair or service present their request forms at the parts department counter. The parts clerk fills a request while the mechanic waits. On average everyday around 210 mechanics arrive in a random fashion over 10-hour working period. It takes the clerk average 2 minutes to fill a request. Assuming the service time and inter-arrival time is random and exponentially distributed. a) What is the average time mechanics spend waiting and having requests filled under the current system