Answer:
 At time 2t the paint ball is at 8 cm to the right and 16 cm to the bottom
Step-by-step explanation:
 We have equation of motion , 
 , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
, s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
 Considering the horizontal motion of paint ball
 Distance traveled during time t = 4 cm
 Initial velocity = u m/s
 Acceleration = 0 

 So 

Now at time 2t, 
 

 So horizontal distance traveled in time 2t = 8 cm to the right
Now considering the vertical motion of paint ball
 Distance traveled during time t = 4 cm
 Initial velocity = 0 m/s
 Acceleration = -g 

 

At time 2t,
 

 So vertical distance traveled in time 2t = 16 cm to the bottom