An inversely proportional equation for our set of circumstances looks like this:
![t= (k)/(r)](https://img.qammunity.org/2019/formulas/mathematics/high-school/vmr5tumeym88s91y72twlk85945di8vppk.png)
. We have a t value of 2 and an r value of 30, so we will sub those values in and solve for k, the constant of variation.
![2= (k)/(30)](https://img.qammunity.org/2019/formulas/mathematics/high-school/8yuqyqgbhr0597ztfqbewaw62jnpagx3by.png)
. Multiply both sides by 30 to get that k = 60. Now we need to find t when r = 50. We can do this now because we have a value for k.
![t= (60)/(50)](https://img.qammunity.org/2019/formulas/mathematics/high-school/89l2mzawcvh4rd2wwv1rizwgo6lp1ul81j.png)
and t = 1.2 hours.