If car is driven at 30 mph during 2 hours, then space (distance) is #d=vt=30t# when t is from 0 to 2

Next: 55 mph the next 5 hours, then #d=55t# when t starts in 2 and finishes in 7 (5 next hours to prior movement). But the car is placed at 60 miles from origin. Then the funtion is #55t-55# because for #t=2#, we have #55·2-55=60#

Finally: 20 mph, then #d=20t# when t starts in 7 and finishes in 8 (next hour to prior movement). But the car is placed at 335 miles because #55·7-50=335#. Then the next movement stars here and the las function will be #20t+195# because for #t=7# we have #20xx7+b=335# this is #b=195#. Finally we have #20t+195#

The best representation to movement is D