The Average Typing Speed S (In Words Per Minute)for a Student

Multiple Choice

The average typing speed S (in words per minute) for a student after t weeks of lessons is given by
$S = \frac { 160 t ^ { 2 } } { 66 + t ^ { 2 } }$
What is the limit of S as t approaches infinity?

A) $\lim _ { t \rightarrow \infty } \frac { 160 t ^ { 2 } } { 66 + t ^ { 2 } } = \frac { 1 } { 66 }$
B) $\lim _ { t \rightarrow \infty } \frac { 160 t ^ { 2 } } { 66 + t ^ { 2 } } = 66$
C) $\lim _ { t \rightarrow \infty } \frac { 160 t ^ { 2 } } { 66 + t ^ { 2 } } = 0$
D) $\lim _ { t \rightarrow \infty } \frac { 160 t ^ { 2 } } { 66 + t ^ { 2 } } = 160$
E) does not exist