Maximum height given hang time and acceleration?

Question

A basketball player achieves a hang time of 0.517 seconds while dunking a ball. The acceleration of gravity is 9.8 m/s/s
What vertical height will he attain?

Answer 1

t(total)=t(up) + t(down)=0.517s

also t(up) = t(down)

then
h=0.5gt^2
h=0.5 x 9.8 x (0.517/2)^2=
h=0.33 m