No.1 You have to learn the formulae for these questions

The one you need is v^2=u^2+2as where u = initial speed v=final speed a=acceleration and s= distance

For you v=0 s=900 a=-32 (because it is traveling upwards) and u is the question

So 0=u^2-(2*32*900) u^2=57600 u= 240