1. The problem statement, all variables and given/known data s varies directly as r and inversely as t. s=10 when r=5 and t=3. What value of t will s=3 and r-4? 2. Relevant equations Direct variation: y=kx; Indirect variation: y=k/x 3. The attempt at a solution I tired s=kr=k/x and plugging in the given, but I could not get t in the end. My real question is how to combine variations, meaning: because s varies directly AND inversely, how do you combine the variations?