Question 318566
D=RT
D=100T for train A.
D=125(T-.2) for train B.
100T=125(T-.2)
100T=125T-25
100T-125T=-25
-25T=25
T=25/25
T=1 HOUR ANS. 
PROOF:
100*1=125(1-.2)
100=125*.8
100=100