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question:There are several sets of three different numbers whose sum is 18, which can be chosen from {1,2,3,4,5,6,7,8,9,10}. How many of these sets contain a 6? A. 3 B. 4 C. 5 D. 6 E. 7

answer:1. **Define the set and condition**: Let the three-element set be {a, b, c}, where a, b, c are distinct elements from the set {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}. We are given that the sum of the elements in the set is 18. 2. **Condition on including 6**: Suppose a = 6. Then, we need to find pairs (b, c) such that b + c = 18 - 6 = 12 and b neq c. 3. **Finding valid pairs (b, c)**: - The possible values for b and c are from the set {1, 2, 3, 4, 5, 7, 8, 9, 10} (excluding 6). - We list the pairs (b, c) such that b + c = 12: - (1, 11) - Not valid as 11 is not in the set. - (2, 10) - (3, 9) - (4, 8) - (5, 7) - Each of these pairs (b, c) is distinct and sums to 12, satisfying the condition b neq c. 4. **Count the number of valid sets**: There are 4 valid pairs (b, c), each forming a valid set with a = 6. Therefore, there are 4 sets containing the number 6 that sum to 18. 5. **Conclusion with boxed answer**: The number of sets containing 6 whose elements sum to 18 is 4. The final answer is boxed{B}

question:In the rectangular coordinate system (xOy), establish a polar coordinate system with the coordinate origin as the pole and the positive semi-axis of x as the polar axis. The curves ({C}_{1}): ρ =4cos θ (0≤θ < frac{π }{2}) and ({C}_{2}): ρ cos θ =3. (1) Find the polar coordinates of the intersection point(s) of ({C}_{1}) and ({C}_{2}); (2) Given point Q on ({C}_{1}) with overrightarrow{OQ}=frac{2}{3}overrightarrow{QP}, find the polar coordinate equation of the moving point P.

answer:(1) Since, the curves ({C}_{1}): ρ =4cos θ (0≤θ < frac{π }{2}) and ({C}_{2}): ρ cos θ =3. Solving the system of equations begin{cases} ρ =4cos θ ρ cos θ =3 end{cases}, we get cos θ=± frac{ sqrt{3}}{2 } , Given 0≤θ < frac{π }{2}, θ= frac{π }{6} , Thus, ρ=2 sqrt{3} , Hence, the polar coordinates of the intersection point of ({C}_{1}) and ({C}_{2}) is boxed{(2 sqrt{3}, frac{π }{6}) }. (2) Let P(ρ,θ), Q(ρ_{0},θ_{0}), and ρ_{0}=4cos θ_{0}, {θ}_{0}∈[0, frac{π }{2}), From the given overrightarrow{OQ} =frac{2}{3} overrightarrow{QP} , we get begin{cases}{ρ}_{0}= frac{2}{5}ρ {θ}_{0}=θend{cases} , Therefore, frac{2}{5}ρ=4cos θ , Thus, the polar coordinate equation of the moving point P is boxed{ρ=10cos θ, θ∈[0, frac{π }{2})}.

question:Last week, my 8th-grade class and I had the opportunity to present our community garden project to the local city council. This project, which involved designing and maintaining a sustainable garden, was a truly transformative experience for all of us. Our students not only learned about plant growth and water conservation but also gained valuable skills in quantitative reasoning and data analysis. One of our students, Alex, took the initiative to develop a method that reduced water usage in the garden by 20%. This small but significant improvement not only helped the garden thrive but also sparked a broader conversation about water conservation in our community. The city council was so impressed by the students' work that they are now considering expanding green spaces in the area. I am incredibly proud of my students and the impact they've had. This project has shown me the power of hands-on, community-focused learning and how it can empower students to make a real difference. If you're an educator or community leader, I encourage you to consider similar projects in your area. Let's work together to create a more sustainable future for the next generation! 🌱 #EnvironmentalEducation #STEMEducation #SustainableFuture #CommunityEngagement

answer:Last week, my 8th-grade class and I had the privilege of presenting our community garden project to the local city council. This initiative, which entailed the design and maintenance of a sustainable garden, proved to be a profoundly transformative experience for all participants. Through this project, our students acquired knowledge about plant growth and water conservation, as well as developed critical skills in quantitative reasoning and data analysis. One of our students, Alex, demonstrated exceptional initiative by devising a method that achieved a 20% reduction in water usage within the garden. This significant improvement not only contributed to the garden's success but also initiated a broader dialogue on water conservation within our community. The city council was deeply impressed by the students' efforts and is now contemplating the expansion of green spaces in the area. I am immensely proud of my students and the impact they have made. This project has underscored the value of hands-on, community-focused education and its potential to empower students to effect real change. For educators and community leaders, I strongly recommend considering similar initiatives in your respective areas. Together, we can collaborate to foster a more sustainable future for the next generation. #EnvironmentalEducation #STEMEducation #SustainableFuture #CommunityEngagement

question:Write a Python function to sort a dictionary where the keys are integers and the values are strings. If the values of two keys are the same, then the keys should be sorted in ascending order. If the dictionary has keys that are not integers, then the function should raise a `TypeError` with the message Dictionary key is not an integer. If the dictionary is empty or None, then the function should return an empty list.

answer:Here's how you can implement this function: ```python def sort_dict_with_int_keys(d: dict) -> list: if d is None or len(d) == 0: return [] if not all(isinstance(k, int) for k in d): raise TypeError(Dictionary key is not an integer) sorted_keys = sorted(k for k in d if isinstance(k, int)) sorted_values = [d[k] for k in sorted_keys] return list(zip(sorted_keys, sorted_values)) ```

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