A55.0 g bullet is fired vertically with an initial velocity of 123m/s

1) what is the velocity at it's highest point of travel?
2) what maximum height does it reach?
3) at what velocity does it hit the ground?

1) at highest point of travel it stops. and there v=0 m/s
3) when it returns to the original point it's speed would be again 123m/s
(conservation law and no calculations needed at all)

2) this one is harder

step 1 - finding the time taken from ground to highest point 
v = u + at
v is the speed at highest point (it's 0, as it stops) 
u - speed at origin (123m/s given)
a - acceleration (in our case it's gravitation and it quals 9.8m/s, some people use just 10 m/s, by the way, it's negative)
0 = 123 + (-9.8)* t
t = 123/9.8 = say 12.3 second
it's time taken to travel up

step 2 - finding displacement or heigh
original formula is 
v^2 = u^2 + 2ar
v - speed at point (0 m/s at the top point)
u - initial speed (123m/s)
a - acceleration (it's gravitation = 9.8 or just 10) and it's again negative
r - displacement or height or distance travelled 
0^2 = 123^2 + 2*(-10)*r
123*123=20r
r= 123*123/20
r= 756 meters 

there is also mass given. it's just to confuse you. no matter that the mass is - time taken, max height or range, acceleration and velocity would be the same for any mass. surprised?