You've often heard about the probabilities — for instance, the likelihood of rain or sunny weather. The probability of 95% sunny weather ensures that a picnic is the best idea; meanwhile, the same chance of rain forces you to stay home.

In this course, we will work with the probabilities, but let's first figure out what a set theory is.

**What is set?**

Set is a collectin of items.

**Examples of sets:**

- Ingredients for the dinner: {Chicken, Carrot, Rice, Ollive oil, Cheese}
- Fruits in basket: {Apple, Orange, Banana, Lemon, Pear}

**Set's Features**

- Elements are distinct
- Elements don't follow any order

**What is set theory?**

Set theory is a branch of mathematics that studies sets and their elements.

Set Theory