$\frac{distane}{\text{t}\text{i}\text{m}\text{e}}$

Problem $2.$ Two children who are bored while waiting for their flight at the airport decide to race from one end of the $20-$m$-$long moving sidewalk to the other and back. Phillippe runs on the sidewalk at $2\mathrm{.}0\frac{m}{s}($relative to the sidewalk$).$ Renee runs on the floor at $2\mathrm{.}0\frac{m}{s}.$ The sidewalk moves at $1\mathrm{.}5\frac{m}{s}$ relative to the floor. Both make the turn instantly with no loss of speed.

a$.$ Who wins the race?

b$.$ By how much time does the winner win?