Answer :
2 hours traveling+1 hour waiting=3 hours, 6hours total-3= 3hours return trip.
X= mph on first leg
2hours*X=3hours*(X-20)
2x=3x-60
-1x=-60
x=60
60mph first leg, 40mph second leg
X= mph on first leg
2hours*X=3hours*(X-20)
2x=3x-60
-1x=-60
x=60
60mph first leg, 40mph second leg