Show work please

An operator is currently operating three identical machines. The operator is utilized 78% of the repeating cycle. Concurrent activity equals 8 minutes and independent operator activity equals 5 minutes. Each operator costs $5 per hour and each machine costs $6 per hour. (a) What is the cost per unit produced based on the minimum cost assign- ment? (b) For what range of values for concurrent activity will the economic assignment equal three machines