In a dart game a target consists of three concentric circles of radii 1, 2, and 3. If a dart sticks inside the circle of radius 1, i. E. Region I, it earns 10 points. If it sticks in region II, the region outside region I but inside the circle of radius 2, it earns 7 points, and if it sticks in region III, i. E. The region outside the circle of radius 2 but inside the circle of radius 3, it earns 4 points. If the dart sticks somewhere within the largest circle, what is the probability of the dart earning 7 points? The answer can be written in simplest terms as ab. What is ab? (Use the / sign in your answer, e. G., 5/7.)