Question

There is a direct variation between m and n. When m = 25, n = 15. Find the constant of proportionality and write the equation for this variation.

Answer 1

Since m and n are in direct variation, when m is 25, n is 15.
$$\begin{gathered} \therefore \frac{m}{n}=k \\ \Rightarrow \frac{25}{15}=k \\ \Rightarrow k=\frac{5}{3} \end{gathered}$$
So, the proportionality constant is $\frac{5}{3}$
The equation of variation is m =$\frac{5}{3}$n