From $5$ p$.$m$.$ to $6$ p$.$m$.,120$ cars checked out of the parking garage at Santa Fe Plaza. Each exiting car took $15$ seconds to pay and wait for the gate to rise before they could exit. How many cars are in the checkout process on average?

Question $19$ Answer

a$.$

$0\mathrm{.}5$ cars

b$.$

$30$ cars

c$.$

$15$ cars

d$.$

$0\mathrm{.}25$ cars