Here's why you get different amounts of tokens for the same amount of money

Do you usually get different amounts of prepaid tokens for the same amount of money everytime you make a purchase? 

Kenya Power has sought to answer the question that has left most Kenyans confused.

The Kenya Power, in a diagram, explained how the process works by comparing electricity units that were bought by a prepaid customer four times for Sh 1,600.

Here’s the illustration;