There are 6 boxes numbered 1, 2,...6. Each box is to be filled up eith...
If only one of the boxes has a green ball, it can be any of the 6 boxes. So, this can be achieved in 6 ways.
If two of the boxes have green balls and then there are 5 consecutive sets of 2 boxes. 12, 23, 34, 45, 56.
Similarly, if 3 of the boxes have green balls, there will be 4 options.
If 4 boxes have green balls, there will be 3 options.
If 5 boxes have green balls, then there will be 2 options.
If all 6 boxes have green balls, then there will be just 1 option.
Total number of options = 6 + 5 + 4 + 3 + 2 + 1 = 21
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There are 6 boxes numbered 1, 2,...6. Each box is to be filled up eith...
Understanding the Problem
To fill the boxes with red or green balls, we need to satisfy two conditions:
- At least one box must contain a green ball.
- Boxes containing green balls must be consecutively numbered.
Identifying the Combinations
Let's denote the number of boxes as 6. We can determine the valid configurations of boxes that contain green balls:
1. 1 Box with Green Ball:
- Options: {1}, {2}, {3}, {4}, {5}, {6}
- Total: 6 combinations
2. 2 Consecutive Boxes with Green Balls:
- Options: {1,2}, {2,3}, {3,4}, {4,5}, {5,6}
- Total: 5 combinations
3. 3 Consecutive Boxes with Green Balls:
- Options: {1,2,3}, {2,3,4}, {3,4,5}, {4,5,6}
- Total: 4 combinations
4. 4 Consecutive Boxes with Green Balls:
- Options: {1,2,3,4}, {2,3,4,5}, {3,4,5,6}
- Total: 3 combinations
5. 5 Consecutive Boxes with Green Balls:
- Options: {1,2,3,4,5}, {2,3,4,5,6}
- Total: 2 combinations
6. 6 Boxes with Green Balls:
- Option: {1,2,3,4,5,6}
- Total: 1 combination
Calculating Total Combinations
Now, we sum all these combinations:
- 6 (1 box)
- + 5 (2 boxes)
- + 4 (3 boxes)
- + 3 (4 boxes)
- + 2 (5 boxes)
- + 1 (6 boxes)
Total = 6 + 5 + 4 + 3 + 2 + 1 = 21
Final Answer
Thus, the total number of ways to fill the boxes under the given constraints is 21. The correct answer is option B.