# solution

A company has started a phone service that uses overseas doctors to provide emergency medical consultations. The responding doctors are based in a country with low wages but with a highly skilled pool of physicians. Responding to each call takes on average 15 minutes. At any given time, there are 4 doctors overseas on duty. Calls arrive every 5 minutes on average (standard deviation is 5 minutes). The company receives \$50 from the patientâ€™s insurance company for each consultation. If one of the 4 overseas doctors is available, the firm pays \$20 to the doctor and makes \$30 in profit. If no doctor is available overseas, the call is rerouted to the U.S. where a local physician answers the question. A local physicians is always available to take a call. In this case, the firm pays the \$50 to the local physician, so thereâ€™s no profit for the company.

What is the probability of a call being answered by a physician in the US?

A. 30.61%

B. 25.61%

C. 15.61%

D. 20.61%

What would be the additional profit if the company managed to have 10 doctors overseas on duty at any given time?

A. \$83.91 per hour

B. \$73.91 per hour

C. \$63.91 per hour