1. Plotting the Points:
- We start by plotting all 7 points on the circumference of the circle. Let's label these points as A1,A2,A3,A4,A5,A6,A7.
2. Labeling the Points:
- Out of these 7 points, Bread selects 4 points to form a quadrilateral. Let's label these points as Q1,Q2,Q3,Q4.
- Kwu then selects the remaining 3 points to form a triangle. Let's label these points as P1,P2,P3.
3. Condition for Non-Intersection:
- For Kwu's triangle to not intersect Bread's quadrilateral, the 3 points P1,P2,P3 must be consecutive on the circle. This ensures that the triangle formed by P1,P2,P3 lies entirely within one of the arcs formed by the quadrilateral Q1,Q2,Q3,Q4.
4. Counting Consecutive Points:
- There are 7 points on the circle. We need to count the number of ways to choose 3 consecutive points out of these 7 points.
- The number of ways to choose 3 consecutive points from 7 points is 7. This is because we can start at any of the 7 points and choose the next two points in a clockwise direction.
5. Total Combinations:
- The total number of ways to choose any 3 points out of 7 is given by the binomial coefficient (37).
- (37)=3!(7−3)!7!=3×2×17×6×5=35
6. Calculating the Probability:
- The probability that Kwu's triangle does not intersect Bread's quadrilateral is the ratio of the number of favorable outcomes (choosing 3 consecutive points) to the total number of outcomes (choosing any 3 points out of 7).
- Probability=Total number of ways to choose 3 pointsNumber of ways to choose 3 consecutive points=357=51
The final answer is 51