Question 280373
D=RT
388=(R+R+3)4
388=(2R+3)4
388=8R+12
8R=388-12
8R=376
8=376/8
R=47 MPH FOR THE SLOWER TRUCK.
47+3=50 MPH FOR THE FASTER TRUCK. 
PROOF:
388=(47+50)4
388=97*4
388=388