Q. Tim and Rick both can run at speed v_r and walk at speed v_w, with v_{rm r} > v_{rm 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 other half.
How long does it take Tim to cover distance?
State the time taken by Tim in terms of v_r, v_w, and D.
Q. Two ants race across a table 72 cm long. One travels at 4.26cm/s and the other at 3.99999 cm/s. When the first one crosses the finish line, how far behind is second one?