To learn how to set up and solve "variation" exercises, try studyinga few online lessons. As they will demonstrate, the general translation is:

. . . . .y varies directly as x: y = kx

. . . . .y varies inversely as x: y = k/x

. . . . .y varies jointly as x and z: y = kxz

Once you've studied some lessons and learned the basic terms and techniques, please attempt the exercise.

Start by translating the English statement into the proper algebraic equation. Then plug the given values in for the given variables, and solve for the variation constant "k".

"The answer" is the equation you started with, but with the value of "k" listed, rather than just the letter.

Have fun!