Determine the Constant of Variation for the Stated Condition $c$ Varies Jointly As

Multiple Choice

Determine the constant of variation for the stated condition.
- $c$ varies jointly as $a$ and $b$ . Find $c$ when $a = 15 , b = 13$ , and $k = 3$ .

A) $\mathrm { c } = 585$
B) $\mathrm { c } = 195$
C) $\mathrm { c } = 65$
D) $\mathrm { c } = \frac { 13 } { 5 }$