Area of large rectangle is 50u and area of shaded rectangle is 21u. Area of unshaded is 29u. 29/50 chance that a point chosen inside the large rectangle is not in the shaded region. If you need a decimal number then you can use the calculator for that.
Let's first find the area, I had a question similar to this in math league. 10 × 5 = 50 7 × 3 = 21 You can subtract the shaded from the total. 50-21=29 Now the probability is 29/50.