A flow line mass production operation consists of eight manual workstations. Work units are moved synchronously and

automatically between stations, with a transfer time of $15sec.$ The manual processing operations performed at the

eight stations take $40sec,52sec,43sec,48sec,30sec,57sec,53sec,$ and $49sec,$ respectively. Determine average

production rate $($pieces$/$hour$).$

a$.75$

b$.100$

C $50$

d$.25$