Tim and Rick both can run at speed v_r and walk at speed v_w, with v_r greater than v_w. They set off together on a journey of distance D. Rick walks half of the distance and runs the other half. Tim walks half of the time and runs the other half. the time it takes tim to cover the distance is: t_R =((D/2)/v_w)+((D/2)/v_r) the time it takes rick to cover the distance is: t_T =2*D/(v_w+v_r) In terms of given quantities, by what amount of time, Delta t, does Tim beat Rick? It will help you check your answer if you simplify it algebraically and check the special case v_r = v_w. Express the difference in time, Delta t in terms of v_r, v_w, and D. this is an easy problem because all i need to do is take the Rick's time minus Tim's time right? i've done it and my answer is incorrect.