PLS HELP ME I DON'T GOT MUCH TIME!!!! I ONLY GOT 1 MIN!!!!

Two sixth grade science classes are making salt water solutions. The first class (Class A) is using a ratio of three parts salt to five parts water. The other class (Class B) is using a ratio of two parts salt to four parts water. Using the amount of water as the independent variable and the amount of salt as the dependent variable, write a function equation for each class to represent its solution. Make sure to indicate which equation belongs to which class.