The Unit Improvement Factor for an 80% Learning Curve at 100

Multiple Choice

The unit improvement factor for an 80% learning curve at 100 units is 0.2271.The first and second timings of a person doing a job are 20 minutes and 16 minutes respectively,what is the learning-adjusted time estimate for unit number 100?

A) 20 minutes
B) 16 minutes
C) 2.271 minutes
D) 4.542 minutes
E) 0.800 minutes