How to specify the number of cards while creating an orthoplan?

Hello seniors,

I need help to specify the number of cards generated when creating an orthoplan design. I read that the default number of cards generated is 8, but when I typed 10, it resulted in 12. I modified the data view of the cards to only 10 cards and also the data of preference to only 10 variabels but the syntax resulted in errors like "too many variabels".

I want only 10 cards of stimulis for my research about hotel preference. Please help.
Thank you before