Exercise 1

A survey shows that 70% of high school students are sensitive to sustainable development. Among them, 80% say they sort their waste. Finally, 64% of students who are not sensitive to sustainable development do not sort their waste. We choose a high school student at random.

1/ Construct a weighted tree describing the situation.

2/ calculate the probability that the student is sensitive to sustainable development and sorts waste.

3/ Calculate the probability that he sorts his waste.

4/ Calculate the probability that it is sensitive to sustainable development knowing that it does not sort its waste.

5/ Using the previous questions, construct a new weighted tree modeling the same experience.

6/ Construct a double-line enrollment table knowing that there are 400 students in this high school.

Exercise 2:

A university only offers 3 courses, A, B or C. Students must enroll in only one of the 3 courses.

We then choose a university student at random. The probability of being enrolled in track A is double that of being enrolled in track B. The probability of being enrolled in track A is triple that of track C. In addition, 20% of those enrolled in stream A are girls (F) compared to 30% for stream B and 40% for stream C.

1/ Events A, B and C therefore form a partition of the universe. By calling (p) the probability of event A, determine an equation verified by (p) then deduce its value.

2/ Construct a weighted tree corresponding to the situation.

3/ Calculate the probability that the student is a boy.

4a/ Calculate the probability that the student is in stream A, knowing that he is a boy.

4b/ Calculate the probability that the student is in sector B, knowing that it is a girl.

Solid Waste Management (SWM) is a multifaceted problem comprising political, socioeconomic, institutional, and environmental aspects. Due to exponential urban growth, it has become one of the most significant issues faced by urban spaces in developing countries. The gap in environmental knowledge among the youth and the old within developing countries contribute to ecological issues or waste management problems, resulting in unsustainable development, with important consequences in low-income countries. For that matter, a systematic review was conducted aiming to identify and analyse environmental knowledge, awareness, attitudes, and practice studies on SWM from 2010 to 2019 in developing countries. The evidence suggests that students at both secondary and tertiary levels have positive environmental attitudes, and high awareness of environmental issues, but there is a lack of practical education of teachers to guide students to put SWM into practice. Student’s low environmental knowledge is related to a deficiency in teachers’ practical experience in SWM for environmental sustainability. A relationship between teachers’ and students’ knowledge and attitudes towards SWM, as well as differences in awareness, attitude, and practices of SWM linked with education and age, were also found. This review also revealed that the lack of environmental education in most developing countries is caused by fragilities in practical environmental curricula of teachers to respond to modern-day environmental issues for sustainable development and cleaner production (CP). To bridge the knowledge gap between the youth and older people in SWM, environmental sustainability education should be integrated into schools at all levels within developing countries.

Keywords: solid waste management (SWM); environmental awareness; environmental education; environmental