In the Following Formula, F(x) Is the Minimum Number of Hours

Multiple Choice

In the following formula, f(x) is the minimum number of hours of studying required to attain a test score of x: $$f ( x ) = \frac { 0.48 x } { 100.5 - x }$$ How many hours of study are needed to score 84?

A) 24.40 hr
B) 4.83 hr
C) 2.44 hr
D) 100.92 hr