To solve this proportion:

Simplify 3/6, it reduces to 1/2

Then do the Criss cross method
1d = 7 ×2
d=14
Hope it helps!
Answer:

Step-by-step explanation:
An apothem is a perpendicular drawn from the centre of the triangle to one of its sides.
The three apothems OD, OE, and OF divide ∆ABC into six smaller congruent triangles.
1. Area of ∆OCD
CotOCD = OD/OC
cot30 = CD/6
√3 = CD/6
CD = 6√3
A= ½bh
A = ½ × 6√3 × 6 = 18√3 in²
2. Area of ∆ABC
A = 6 × area of ∆OCD = 6 × 18√3 = 108√3 in²

Its a 2 hour difference between both of those speed limits. 13 hours for the old speed limit, and 11 for the current speed limit. Hope i could help!