Arthur and Robin both can run at speed v_r and walk at speed v_w, with v_r > v_w. They set off together on a journey of distance D. Robin walks half of the distance and runs the other half. Arthur walks half of the time and runs the other half.
How long does it take Robin to cover the distance D?
Express the time taken by Robin in terms of v_r, v_w, and D.
v = d/t and t = d/v
The Attempt at a Solution
total time = (D/2)/(v_w) + (D/2)/(v_r)
= D/(2v_w) + D/(2v_r)
I just wanted to check before I submit this , thanks for any help