1. The problem statement, all variables and given/known data

A firefighter on the street is trying to spray water from a hose to a building a horizontal distance x_{1}through a window a heighthabove the height of the hose (see figure in image below). For a given initial speed v_{o}of water from the hose, we would like to future out if the water will reach the window, and if it does, then what angle (and how many angles are there) does he need to aim the hose at. (The questions are in the image below)

2. Relevant equations

t = d / (v cos θ)

h = -4.9 sin θ t^2 + v sin θ t

I posted this on a different web forum, however, I had no luck with hints. I figured it may be because it is very math intense, that is why I am posting this on here. My question, is how can you solve for b) (i-iii) if you have so many unknown variables?