Round to Two Decimal Places Unless Otherwise Indicated $\mathrm { y }$

Multiple Choice

Round to two decimal places unless otherwise indicated.
If the average cost per unit C(x) to produce x units of plywood is given by C(x) , what is the
-In the following formula, $\mathrm { y }$ is the minimum number of hours of studying required to attain a test score of $\mathrm { x } : \mathrm { y } = \frac { 0.48 \mathrm { x } } { 100.5 - \mathrm { x } }$ . How many hours of study are needed to score 91 ?

A) $9.63 \mathrm { hr }$
B) $4.60 \mathrm { hr }$
C) $99.97 \mathrm { hr }$
D) $46.00 \mathrm { hr }$