National Council of Examiners for Engineering and Surveying (NCEES) Fundamentals of Engineering (FE) Industrial and Systems Practice Exam

To determine the time needed for the 30th unit in a process with an 80% learning curve, we start by understanding the implications of a learning curve in manufacturing. The learning curve effect indicates that as more units of a product are produced, the time taken to produce each subsequent unit decreases at a predictable rate.

In this case, the learning curve percentage is 80%, suggesting that with each doubling of production quantity (e.g., from 10 to 20 units), the time required to produce the next sets of units will be 80% of the previous time taken for the same number of units.

The time for the 10th unit has been given as 90 minutes. The formula to calculate the time for a specific unit (T_n) using a learning curve is:

\[

T_n = T_1 \times n^{\log_2LR}

\]

Where:

- \( T_1 \) is the time for the first unit,

- \( n \) is the unit number,

- \( LR \) is the learning rate (in this case, 0.8),

- \( \log_2LR \) is the log of the learning rate to base 2.

To find the