# calculus

posted by
**Adam Janky**
.

The data entry speed (in entries per minute) of a data clerk trainee is represented by the following equation, where x is the number of hours of training he has had.

S = 10

0.8x + 4

, 0 ≤ x ≤ 100

What is the rate at which his speed is changing and what does this rate mean when he has had the following hours of training?

(a) 15 hours of training

(b) 40 hours of training