Answer
8
Work Step by Step
The number of ways in which a series of successive things can occur is found by multiplying the number of ways in which each thing can occur.
----------
1. The gender of the customer can be chosen in 2 ways.
2. The age group of the customer can be chosen in 2 ways.
3. The type of payment can be chosen in 2 ways.
Applying the Principle,
the total number of shopper categories is 2$\times$2$\times$2$=8$