The rink has a dimension of 200 ft* 85 ft = 17000
![ft^(2)](https://img.qammunity.org/2019/formulas/mathematics/college/61u872k4yewxqa89ywd6g1geri9ggx6oop.png)
depth = 1.5 inch that becomes
= 0.125 ft
So total volume of the water required = 17000* 0.125 = 2125
![ft^3](https://img.qammunity.org/2019/formulas/mathematics/college/4tc81mhcq08nwxikxg81kuacu8nhowib4n.png)
Now 1 cubic foot of water= 7.480 gallons
Hence total gallons required are 2125 * 7.480 gallons = 15895 gallons.