The reciprocal of a number is defined as 1 divided by that number. In the case of 1/5, the reciprocal can be calculated by flipping the fraction. This means you take the denominator (which is 5) and make it the numerator, and you take the numerator (which is 1) and make it the denominator.
So, the reciprocal of 1/5 is:
5/1
or simply 5.
To summarize, the reciprocal of 1/5 is 5, because if you multiply 1/5 by its reciprocal (5), you will get 1:
(1/5) × 5 = 1.