4 solutions to overcome overcrowding in cities:

1. Promote economic development in rural areas. This will create more jobs and opportunities in rural areas, reducing the need for people to migrate to cities.
2. Invest in infrastructure in cities. This will improve the quality of life in cities and make them more attractive places to live.
3. Expand public transportation. This will make it easier for people to get around cities without having to use cars, which will help to reduce congestion.
4. Encourage people to live in smaller spaces. This will free up more space in cities for other uses.

4 solutions to overcome poverty:

1. Create jobs. This is the most important step in reducing poverty. Governments can create jobs by investing in infrastructure, education, and healthcare.
2. Provide education and training. This will help people to develop the skills they need to get good jobs.
3. Expand social safety nets. This will provide a safety net for people who are unable to work.
4. Reduce inequality. This can be done by taxing the wealthy more and redistributing income.

4 solutions to overcome the lack of clean water:

1. Invest in water infrastructure. This includes building dams, reservoirs, and water treatment plants.
2. Protect water sources. This includes reducing pollution and deforestation.
3. Educate people about water conservation. This will help people to use water more efficiently.
4. Develop new technologies for water purification. This will make it easier to provide clean water to people in remote areas.

4 solutions to overcome crime:

1. Invest in education and social programs. This will help to reduce poverty and inequality, which are root causes of crime.
2. Enforce the law fairly and consistently. This will send a message that crime will not be tolerated.
3. Provide rehabilitation programs for offenders. This will help offenders to reintegrate into society and reduce the likelihood that they will reoffend.
4. Create safe and supportive communities. This includes providing opportunities for people to get involved in their communities and build relationships with their neighbors.