Answer:

Explanation:
Given:
A square (all sides are equal)
AC = 20 (diagonal)
PI = 7
First, we can find the side length of the whole square:


Divide both sides of the equation by √2 to make a the subject:

Now, let's do the same thing, but with the smaller square on the top right:



We also have to find the areas of the shaded rectangles and the whole square:


Let's call the event A:
A - "The dart hits the shaded region"
All outcomes:
n = 200 (since it can randomly hit the whole area)
Favorable outcomes:
m (A) = 45,5 (since it only need to hit the shaded region)
