A cell phone repair shop consists of three processes. Step 1 requires 4 minutes per unit, step 2 requires 5 minutes per unit, and step 3 requires 5 mins per unit. 30% of units that complete the third step require rework, which means those units must start the process over at step 2 (processing times are the same for units being reworked) and rework is always successful. Demand at the shop is 0.3 units per minute. what is the capacity of the shop ( in units per minute)?

capacity in units per minute