Một công ty sản xuất thuốc trừ sâu cần làm hai loại thuốc trừ sâu A, B được yêu cầu phải sản xuất ít nhất 20 kg thuốc loại A và 20 kg thuốc loại B khối lượng thuốc loại A phải nhiều hơn khối lượng thuốc loại B ít nhất là 10 kg. Để sản xuất được 1 kg thuốc loại A cần 1 kg nguyên liệu I và 2 kg nguyên liệu II; sản xuất 1 kg thuốc loại B cần 1 kg nguyên liệu loại I và 1 kg nguyên liệu loại II. Biết trong kho của công ty hiện còn 70 kg nguyên liệu loại I và 110 kg nguyên liệu loại II. Biết giá của 1 kg nguyên liệu loại I là 200 nghìn đồng và giá của 1 kg nguyên liệu loại II là 350 nghìn đồng. Để chi phí sản xuất là nhỏ nhất thì công ty phải sản xuất bao nhiêu kg thuốc loại A?
Bộ Đề Kiểm Tra Giữa Học Kì I - Toán 10 - Chân Trời Sáng Tạo là tài liệu cung cấp bài tập chuyên sâu, tập trung vào các kiến thức cốt lõi như hàm số bậc nhất, bậc hai, phương trình, bất phương trình, và căn bậc hai. Đề thi được thiết kế với các câu hỏi đa dạng, từ việc nhận diện đặc điểm hàm số đến giải phương trình phức tạp, giúp học sinh rèn luyện kỹ năng phân tích và tư duy giải toán logic. Đây là tài liệu cần thiết để học sinh làm quen với các dạng bài toán nâng cao, tối ưu hóa kỹ năng tính toán và lập luận, tạo nền tảng vững chắc cho các kỳ thi tiếp theo.
Câu hỏi liên quan
Cho hình chóp S.ABCD có đáy ABCD là hình thoi cạnh a và SA = SB = SC = a.
Mặt phẳng (ABCD) vuông góc với mặt phẳng:
Một người bơi dọc trong bể bơi dài 50 m. Bơi từ đầu bể đến cuối bể hết 20 s, bơi tiếp từ cuối bể quay về đầu bể hết 22 s. Xác định vận tốc trung bình trong trường hợp bơi từ cuối bể về đầu bể
Trong mặt phẳng \(Oxy\), cho đường tròn \(\left( C \right)\) có phương trình \({{x}^{2}}+{{y}^{2}}-6x+2y+6=0\) và hai điểm \(A\left( 1;-1 \right),B\left( 1;3 \right)\).
Khẳng định nào sau đây đúng?Những tranh cãi về đạo đức trong việc ứng dụng đột biến gene chủ yếu xuất phát từ:
Acetylsalicylic acid (thuốc Aspirin) có công thức cấu tạo như hình bên. Phát biểu nào sau đây là không đúng?
Read the following passage about managing change and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
Growing up in Athens, Greece, Lydia Borsi remembers feeling tested when she tried to deal with mental health issues. Borsi says she had been seeing a therapist for anxiety. But she notes that people in Greece do not openly discuss mental health issues, which also get little attention in general healthcare services. “It was a lot more secretive. And people thought that I was a lot more unique,” Borsi said.
That all changed in 2017 when she moved to the United States to study at the University of Rochester in Rochester, New York. “When I came here, I really liked that people were not afraid to speak up about mental health and say that it’s important,” she said. The university was very supportive of her needs and offered plenty of information. She also became involved with a school group called Active Minds that helps students deal with mental health issues. [A]
Then due to the spread of the novel coronavirus, the University of Rochester had to move all its classes and some of its mental health resources online. Luckily, Borsi was able to connect with a mental health expert outside the school, in the local community. [B]
But as many of her American friends returned home, Borsi was stuck. Greece had succeeded in limiting the spread of the virus within its borders, but flights there from the U.S. are barred until July. Also, the health crisis has put her plans to seek admission to medical school in Britain on hold. [C] And she is not alone.
[D] In April, Active Minds launched a survey of over 2,000 students at U.S. colleges and universities. The study found that over 80 percent of those asked said the coronavirus crisis had negatively affected their mental health. One in five said it has affected them severely.
Laura Horne, chief program officer at Active Minds, says the findings are especially troubling given that the crisis is only going to make it harder for colleges and universities to help these students. “Colleges and universities had to pivot rather quickly to respond to COVID-19 and figure out all facets of university life, including mental health services. Now they have to figure out how to communicate with students,” Horne said.
Frank Chen is a Houston, Texas-based psychiatrist who has worked with college-age young adults. He points out that individuals at that age are in an important stage of their mental development. And college can be a difficult experience for students with or without mental health issues, as they balance work, studies, and personal relationships. Adding a major world event, like the spread of the coronavirus, makes it very difficult to predict what the long-term psychological effects might be. “I don’t think that there’s another event in the history of the people who are alive now that can really measure up to this,” said Chen.
Which of the following is NOT mentioned by Frank Chen as a factor affecting college students’ mental health?
Em hãy chọn phương án đúng nhất. Pha ban đầu của dao động điều hoà phụ thuộc vào
Virut tự nó không có khả năng xâm nhập vào tế bào thực vật là do cấu trúc nào sau đây?
If energy _______ inexpensive and unlimited, many things in the world would be different.
Mark the letter A, B, C, or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.
a. Tom: Where did you fly to?
b. Lydia: No, we went to Portugal. And we went in August.
c. Tom: Did you go to Spain in July?
d. Lydia: We drove there, actually.
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12.
MAKE A DIFFERENCE – VOLUNTEER TODAY!
Let’s look at how volunteering can change lives and improve our community.
Facts and Figures:
Did you know that millions of people volunteer every year? Volunteers help in hospitals, schools, animal (7)________, and community centers. They bring people together, improve lives, and support those in need. Studies (8)________ that people who volunteer feel happier and more connected to their (9)________.
Positive Actions!
● Find a cause you care about. (10)_________ it’s helping children, protecting the environment, or caring for animals, there are many ways to get involved.
● Start small and be consistent. Even a few hours a month can make a big (11)________. Volunteering regularly helps build trust and strong connections with those you help.
● Learn new skills and meet (12)________ people. Volunteering is a great way to gain experience and make friends, all while helping others.
Khối lượng nguyên tử sodium (kí hiệu là Na) là 38,1643.10–27 kg và theo định nghĩa 1 amu = 1,6605.10–27 kg. Khối lượng mol nguyên tử Na (g/mol) và khối lượng nguyên tử Na (amu) lần lượt là
Khi đến hạn, bên vay tín dụng sẽ có nghĩa vụ gì?
Read the following passage about lifelong learning and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
My father was an enthusiastic traveller, but as he got older, he increasingly suffered from what he called “travel fever,” a vivid term for the acute anxiety felt before a journey, essentially due to uncertainty about all the things that could go wrong. Sadly, this eventually stopped him from going on holiday. Then I, too, started to suffer similar apprehension, so I consulted a psychotherapist. She recommended a small piece of cognitive behavioural therapy, which involved acknowledging the mental and physical symptoms of anxiety, but telling myself that these were essentially indistinguishable from feelings of excitement about the prospect of a journey. This reframing of my feelings has been reasonably effective – it’s one way of dealing with uncertainty.
It’s not just the uncertainty of travel that we all have to face. None of us knows what is going to happen, or what is currently going on outside our immediate knowledge, or the vast majority of what has happened in the past. Uncertainty has been called the “conscious awareness of ignorance,” and there is a lot we are ignorant about. We must navigate through life without complete information, and this fundamental uncertainty is an inescapable aspect of human existence.
We all have to live with this uncertainty and, as a statistician, it’s been my job to try to analyse data and assess some of the risks we face. (I)But some deal with uncertainty with more equanimity than others. (II) Psychological studies, as well as our own experience, reveal a wide variation in people’s responses, including those that are cognitive (how we think), emotional (how we feel), and behavioural (what we do). (III)For example, when faced with uncertainty, do you deny it or acknowledge it, does it put the wind up you or make you courageous, do you try to avoid it or approach it?(IV)
Of course, your response may depend on the context, just as an individual’s appetite for risk-taking can vary across different areas of their lives. I have known people who seemed to take huge physical risks, yet were very cautious with money. Numerous scales have been developed to measure how well people can deal with uncertainty, based on responses to statements ranging from “Unforeseen events upset me greatly” to “When it’s time to act, uncertainty paralyses me.” Those who score highly, and find it difficult to tolerate uncertainty, may also be at increased risk of clinically significant anxiety and depression.
Which of the following best summarizes paragraph 4?
Sử thi Đăm Săn là sử thi của dân tộc nào?
Sau Chiến tranh lạnh, hầu hết các quốc gia đều điều chỉnh chiến lược, tập trung vào phát triển:
Tỉ số nén là?
Cho hàm số \(f\left( x \right)\) xác định và có đạo hàm đến cấp hai trên \(\mathbb{R}\), thỏa mãn phương trình
\({{\left( {f}'\left( x \right) \right)}^{2}}+f\left( x \right)\cdot {f}''\left( x \right)=\) \(20{{x}^{4}}+12{{x}^{2}}+9,\forall x\in \mathbb{R}\) và \(f\left( 0 \right)=0\).
Biết rằng vế trái của phương trình có thể biểu diễn dưới dạng đạo hàm của một hàm số.
Mỗi phát biểu sau là đúng hay sai?
Khẳng định nào dưới đây là sai khi nói về máy tính?
Khi quả bóng đó bị nổ, nhiệt độ của khí bằng bao nhiêu?
