INFORMATION TABLE

Counter$($s$)$

A

B

C

D

E

F

Activity Time

$10$ secs$.$

$30$ secs$.$

$60$ secs$.$

$40$ secs$.$

$30$ secs$.$

$20$ secs$.$

Wage per Person per Hour

$$6$

$7$

$7$

$7$

$7$

$8$

Refer to Exhibit $5-1.$ How many customers can this cafeteria process in an hour?

a$.180$

b$.90$

c$.120$

d$.360$