Let : x=time to and y=time from....x+y=2
Let T=speed to and H=time from T=H+8
xT = yH = 6
y=6/H and x = 6/T = 6/(H+8)
(6/H) + [6/(H+8)] = 2
6H + 48 + 6H = 2H2 + 16H
2H2 + 4H - 48 = 0 => H2 + 2H - 24 =0
H = [-2 + sqrt(4+96)]/2 = 4
T = 12
y=6/4 = 3/2
x=6/12 = 1/2
x+y = 4 as required