That's easy it is 11/8 because 4+7=11 8 will be the same
Consider a trapezoid GJKF with:
GH=JH (hypothesis)
FL=KL (hypothesis)
so HL is the median of trapezoid GJKF
so: HL=1/2(2.5+1.2)=1.85
2.5 hours, because 10 miles an hour times 2 = 20 plus half the time? 2.5