urbo Underwriting offers customized loans. Customers call a toll$-$free number with a specific loan request, and typically obtain a response the same day. Turbo Underwriting$$s business process includes six activities which must be conducted in the sequence described below. $($The time required for each activity is shown in parenthesis$).$

Activity $1$: Answer customer call and record key information. $(4$ minutes$/$loan application$),$

Activity $2$: Gather and format the information $($obtain credit scores, organize customer specific needs$)$ for analysis $(5$ minutes $/$ loan application$),$

Activity $3$: Analyze the information: Check the credit worthiness and decide loan amount and APR to offer. $(7$ minutes$/$loan application$),$

Activity $4$: Collect social media information about the customer and feed this information into a proprietary machine learning system $(4$ minutes $/$ loan application$)$

Activity $5$: Perform final checks on loan offer $(2$ minutes $/$ loan application$),$

Activity $6$: Call customer back with the new loan offer and close or inform about the rejection decision. $(5$ minutes $/$ loan application$).$

All six activities need to be carried out, independent of the customer$$s loan application being accepted or not. The whole process is conducted by four associates.

Associate $1$ performs activity $1$ and $2$

Associate $2$ performs activity $3$

Associate $3$ performs activity $4$ and $5$

Associate $4$ performs activity $6$

Each associate is paid $$50$ per hour. You can assume that there exists unlimited demand and that loans are only entering the process at the rate of the bottleneck.

How much time $($in minutes$)$ does it take to handle $20$ loan requests starting from an empty system?