# How do you evaluate 11C7?

##### 1 Answer

See below.

#### Explanation:

The general formula for combinations is:

Where

This notation can seem confusing at first, but it basically just means the following:

etc.

Using formula:

We can make the calculation easier by cancelling first:

This leaves us:

As a quick tip. Notice that what we are removing from the numerator is

What remains in the denominator is #11 - 7 = 4.

This is the

We know this at the start because we had the 11 and the 7'

These are the quick ways of evaluating by hand. A calculator is much quicker, but where's the fun in that :)

Hope this helps you.