The Quick Change Car Care Center $($QCCCC$)$ has six garages equipped with mechanics all in a row, just aching to change your oil while you wait in your car. Customers needing oil changes arrive every thirty minutes with a cv$=1.$ QCCCC also features musical theater in the far end of the garage $($the current production is Cats!$)$ which is necessary because the mechanics are all painfully slow. It takes them on average two and a half hours $($which is roughly the run time of the musical$)$ to change the oil $($with an equivalent standard deviation$).$ For this level of entertainment, they can charge a premium, $$100$ for a basic oil change. They operate $24$ hours a day, seven days a week, and are closed only on Mardi Gras. There's no oil change like an oil change while enjoying Andrew Lloyd Webber's Cats! so if potential customers can't pull in for an oil change, they leave.

The City of Edmond passes legislation that requires every oil change business to be able to handle $90\%$ of their customers immediately. How many bays should QCCCC have?

Question $25$ options:

$7$

$5$

$6$

$8$

Hide hint for Question $25$

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