Determine the Constant of Variation for the Stated Condition $y$ Varies Directly As

Multiple Choice

Determine the constant of variation for the stated condition.
-If $y$ varies directly as $x$ , and $y = 3$ when $x = 5$ , find $y$ when $x = 20$ .

A) 12
B) $\frac { 3 } { 4 }$
C) $\frac { 100 } { 3 }$
D) $\frac { 4 } { 3 }$