Answer:
The direct variation says that:
\(y \propto x\) then;
the equation is of the form:
y = kx , where k is the constant of variation.
As per the given statement:
R varies directly with S.
By definition of direct variation:
\(R = kS\)
Substitute the given values S = 16 and R = 80 to solve for k;
\(80 = 16k\)
Divide both sides by 16 we get;
5 = k
⇒R=5S
Therefore, the constant of variation is, 5
