The figure below shows a shaded rectangular region inside a large rectangle:

A rectangle of length 10 units and width 5 units is shown. Inside this rectangle is a smaller rectangle of length 4 units and width 3 units placed symmetrically inside the larger rectangle. The smaller rectangle is shaded gray.
What is the probability that a point chosen inside the large rectangle is not in the shaded region?
76%
50%
24%
12%