Find the Constant of Variation K $k = 320$ B) $k = \frac { 16 } { 5 }$

Multiple Choice

Find the constant of variation k.
-y varies directly as x. When x is 16, y is 20.

A) $k = 320$
B) $k = \frac { 16 } { 5 }$
C) $k = \frac { 5 } { 4 }$
D) $k = 80$