Question 323432
D=RT
D=40T  FIRST TRIP
D=45(4-T) RETURN TRIP
THE DISTANCES ARE THE SAME TEREFORE THE EQUATIONS ARE THE SAME.
40T=45(4-T)
40T=180-45T
40t+45T=180
85T=180
T=180/85
T=2.118 HRS. FOR THE FIRST TRIP.
4-2.118=1.88 HRS. FOR THE RETURN TRIP.
PROOF:
40*2.118=45*1.88
84.7~84.7 
2*84.7=169.4 MILES IS THE DISTANCE OF THE ROUND TRIP.