A stone is thrown upwards with an initial velocity of 25m/s at an angle of 30 degree to the ground then without any calculation state what the stone vertical velocity will be when it again reaches ground level

The stone's vertical velocity when it reaches ground level will be 0 m/s.

The same as on the way up but now down

-25 sin 30 = -25/2 = -12.5 m/s