Yay projectile motion!

Ok, I think I have it figured out, I just need someone to check my answer. It's nothing hard, I just suck at this type of thing.

Problem: A bullet is fired from the top of an 80 meter tall building at 25 degrees to the horizontal, at 75m/s.

(a) How long does the bullet take to reach its maximum height from the top of the building.

(b) How long does the bullet take to reach the ground.

(c) How far does it get from the base of the building?

The answers I have gotten:

(a) 3.23 seconds
(b) 9.66 seconds
(c) 656.9 meters

Fucking disregard that shit, apparently using trig functions on objects with parabolic motions only works when you're figuring vectors, and not actual distance covered. Christ I'm a dumbass.

big dummy.

break it into x and y components

For (a)

Let vy = y-component of the projectile velocity, so vy=31.70 m/s
Let y(t) = vertical displacement of the projectile at time t. It is affected by gravity, so y(t) = t*vy - 0.5*g*t^2

Think of y(t) as a parabolic curve. You want y(t) maximum, so set dy(t)/dt = 0:
0 = dy(t)/dt
0 = vy - gt
t = vy/g
t = 31.7/9.8
t = 3.23