Help in case study,

case study is Kristen's Cookie Company case

Question is:$-$ Assume that

the roommate is sick so Kristen has to set the timer, pack and accept payment herself $($on top of her usual tasks$)$;

all orders are for two dozen cookies;

starting at $8$pm until midnight, a customer places an order every $30$ minutes $($that is the first customer places an order at $8$pm$,$ the second places an order at $8$:$30$pm$,$ the third places an order at $9$pm$,$ etc. until the last order at midnight$)$;

customers are there to pay for the orders as soon as they are completed.

for washing and mixing step it takes $6$ minutes, as for one dozen cookies, spooning cookies onto tray takes $2$ minutes per tray, till here all the steps are perfomed by kristens. Now her roomate will perfome rest of the next steps set the thermostat ane timer is about $1$ minute, cookies baking takes $9$ minutes, cookie cooling time is $5$ minutes, it takes $2$ minutes to pack each dozen cookies and about $1$ minutes to accept payment fo the order.

how many orders can Kristen process $($i$.$e$.,$ complete$)$ in the first $4$ hours, i$.$e$.,$ from $8$ pm to midnight? Explain why this number differs from the answer to "what is the maximum number of orders that Kristen could process $($i$.$e$.,$ complete$)$ in a period of $4$ hours"?