Launched Horizontally?

[lolseeker2]

A projectile is launched horizontally at A w/ a speed of V. The time flight is 8 seconds and the path of the projectile at B is inclined by 15 degrees w/ the horizontal.
A. What is the V at A?
B. What is the range?
C. What is the launched height?
https://imgur.com/a/SJjWjuj

I tried solving for V at A using (gt/2sin15) = V.
For range, R = (2sin15cos15V^2)/g
For height, H = V^2(sin^2(15))/2g

Are these the correct formulas?

 

[haruspex]

Are these the correct formulas?

No. Where did you get these formulas from? If they are not accompanied by some description of the context in which they apply then they are of no use and might as well be ditched.

In the vertical direction, what change of speed would you expect in time t?