You throw a beanbag at a wall with 7 colored squares, each with an area of 1/4^2. If you hit a square, you win a prize. What is the probability of winning a prize?
You need more information. For starters:
1) what is the total area of the wall?
2) Are landings on the wall random?
or, does the fact that some people may aim their throws actually make a difference.