Consider the Following Assembly Line Information for Manufacturing the Latest

Multiple Choice

Consider the following assembly line information for manufacturing the latest cell phone in Table 2. The firm wants to produce 80 cell phones per hour.
Table 2
$\begin{array}{ccc}\text { Task } & \text { Time (n minutes) } & \text { Predecessor(s) } \\\text { A } & 0.5 & \text { none } \\\text { B } & 0.4 & \text { A } \\\text { C } & 0.6 & \text { A } \\\text { D } & 0.2 & \text { B, C } \\\text { E } & 0.3 & \text { B } \\\text { F } & 0.7 & \text { E, D } \\\text { G } & 0.4 & \text { F C }\end{array}$
-Using the longest-task-time rule, the efficiency of an assembly-line balance is _____.

A) Less than 65%
B) more than 65% but less than 75%
C) more than 75% but less than 85%
D) more than 85% but less than 95%