If the door lock of an old door in a rental apartment is not functional, you can try a few things to make it work. First, try lubricating the lock with a silicone-based lubricant to see if that helps it turn more smoothly. If that doesn't work, you may need to tighten or adjust the screws and hardware on the door to ensure that the lock is properly aligned. If these steps don't work, it's best to contact the landlord or property manager to have a professional locksmith come and repair or replace the lock. **

Living in a functional shared apartment can be a great experience for those who enjoy social interactions and sharing responsibilities. It can create a sense of community and camaraderie among the residents. However, it also requires good communication, respect for each other's space, and a willingness to compromise on certain aspects of daily living. Overall, it can be a rewarding and cost-effective way to live, especially for young adults or individuals looking to save money on rent. **

Complementary goods are products that are typically used together, such as peanut butter and jelly. When the price of one complementary good increases, the demand for the other complementary good may decrease. Substitute goods are products that can be used in place of each other, such as butter and margarine. When the price of one substitute good increases, the demand for the other substitute good may increase. Indifferent goods are products that consumers see as interchangeable and are indifferent between the two, such as two different brands of bottled water. **

Functional equations are equations where the unknowns are functions rather than variables. They involve relationships between a function and its arguments, and often require finding a function that satisfies the given conditions. Functional equations can be found in various branches of mathematics, such as analysis, algebra, and combinatorics, and are used to describe how a function behaves in relation to its inputs. Solving functional equations typically involves techniques such as substitution, manipulation, and sometimes advanced mathematical tools like calculus or complex analysis. **

Functional jackets are outerwear designed with specific features to serve a practical purpose. These jackets are often made with technical materials that provide protection against the elements, such as wind, rain, or snow. They may also include features like adjustable hoods, multiple pockets for storage, and ventilation options for increased comfort during outdoor activities. Functional jackets are popular among outdoor enthusiasts, athletes, and anyone looking for versatile and durable outerwear. **

Functional music refers to music that is created with a specific purpose or function in mind, such as to enhance a particular activity or environment. This can include music for relaxation, concentration, exercise, or even to create a certain mood in a film or video game. Functional music is designed to serve a practical function beyond just listening for enjoyment, and is often tailored to the needs of the listener or the context in which it will be used. **

Yes, the smartwatch is functional. It is designed to perform a variety of tasks such as tracking fitness activities, monitoring heart rate, receiving notifications, making calls, and even accessing apps. Its functionality can vary depending on the model and brand, but overall, smartwatches are designed to be practical and useful devices for everyday use. **

Functional games are games that are designed with a specific purpose in mind, such as teaching a skill, promoting a behavior, or providing a therapeutic benefit. These games are often used in educational settings, healthcare, or corporate training to engage and motivate participants while achieving a specific goal. Functional games can take many forms, including board games, video games, or physical activities, and are designed to be enjoyable and engaging while also serving a practical purpose. **