How do I make a purchase without the security questions
i have been trying to purchase a book from the iBook store but the system keeps asking me to set up three security questions to better authenticate my purchases in the future. I set them up, plus a rescue email address and then click on done. It then asks if I want to complete my purchase, I say yes and then it opens up the window to tell me to set up these seciruty questions again. I've done it three times now and am still not able to purchase a book. If I say cancel, it stops the attempted purchase as well. Immediately before this, I had purchased a book and wasn't forced to set up security questions. Do not not what to do now.
iPad (3rd gen) Wi-Fi, iOS 9.1