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Set theory is used as a foundation for many subfields of mathematics and computer science. Let us explore two areas.

#### Sets in Data science

A dataset is a collection of numbers or values that relate to a particular subject. A public health authority may maintain a dataset of community health records.

Your local public health authority has decided to support people with cardiac risk by offering healthy lifestyle programs. They wish to make a list of vulnerable community members based on the following criteria: people with hypertension, people aged over 60, and obese people who also have a family history of cardiac issues. Can you help them extract data to make a contact list?

Let H be the set of people with hypertension, A the set of people aged over 60, O the set of obese people, and F the set of people with family history of cardiac issues.

The set of people who are vulnerable = H ∪ A ∪ (O ⋂ F)

#### Sets in Databases

In databases, records within a table can be treated as objects in a set - i.e. the table becomes a set of records.

SQL (Structured Query Language) is used to communicate with a database. SQL statements are used to perform tasks such as update data on a database, or retrieve data from a database.

Amazon maintains a database of customers and orders. To contact all customers who have placed orders, we need to find the intersection of the customers and orders table. The SQL `Inner Join` is just the intersection of two sets.

### Instructions

Let us look at a daily life example of sets. Can you list the sets you would find in your kitchen?

In a kitchen, the plates are kept separate from bowls and cups. Sets of similar utensils are grouped together. Sets of food-items are kept separate from sets of cleaning-aids.