Posted by mohlomphegi on Friday, August 30, 2013 at 3:53am.
since the range and max height are
r = v^2 sin2θ/g = 25
h = v^2 sin^2θ/2g = 6
tanθ = 24/25
so you can find the initial v.
And of course, the height y is
y = vt - g/2 t^2
set y=0 to find the flight time t.