Option B;
A suitable x-coefficient for a quadratic function that factors into a perfect square has to be even.
Well, it is

. That is, the equation is

. The run could be found when y=0, so

or

or

or

. 375 inches. 30 feet means 360 inches, as far as I remember (in my country only metric systems are being used :) ) so it doesn't really work -- the ramp is just a bit too long.
Yes; they have the same side lengths and angles
You would do DRT, distance, rate, time. Rate us what you want. R=T/D- so you would divide 5/6 by 7/10 to get which is 1.1904