A number is reciprocal when the multiplication of these two numbers results in 1.
For example, let's find the reciprocal of 6, to find it we must think, which number multiplies 6 and results in 1?
The answer is 1/6, that's the only number that multiplies 6 and the result is 1.
Using that logic, we have simple ways to find the reciprocal of a number.
First step - Write the number as a fraction
Before we find the reciprocal, we write ou number as a fraction, let's use 8 now. How do we write 8 as a fraction?
Simple! we just put 1 as the denominator:

Second step - Flip the fraction
Now we have the number in the fraction notation we just flip it to find the reciprocal.

The flipped fraction is the reciprocal
Therefore, what's the reciprocal of 8? 1/8
Now, let's solve the problem, in fact, we want to find the reciprocal of

As we can see it's already in the fraction notation, then, let's just flip the fraction

When we flip it we get 11/1, which is basically 11. Therefore, the reciprocal of 1/11 is 11.