One little piece of information I think you left out of your question:
WHERE did the earthquake occur ? ?
It's going to make a big difference.
Are there any options or is it not multiple choice.
<u>Answer:</u>
At time 2t the paint ball is at 8 cm to the right and 16 cm to the bottom
<u>Explanation:</u>
We have equation of motion ,
, 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