An operation is to be done in a single shift, $8$ hours per day with $50$ minutes per day downtime $($operator allowance where the machine is also idle$).$ The operation is expected to have an $85\%$ performance and the following parts are to be run using this same machining process:

Part A$,$ requirement is $10,000$ per week, time standard $=0\mathrm{.}3386$ min$/$part

Part B$,$ requirement is $15,000$ per week, time standard $=0\mathrm{.}2956$ min$/$part

Part C$,$ requirement is $20,000$ per week, time standard $=0\mathrm{.}2038$ min$/$part